WO2012127019A1

WO2012127019A1 - Mechanical movement for a chronograph watch

Info

Publication number: WO2012127019A1
Application number: PCT/EP2012/055157
Authority: WO
Inventors: Guy Semon; Yannick Chatelain
Original assignee: Lvmh Swiss Manufactures Sa
Priority date: 2011-03-22
Filing date: 2012-03-22
Publication date: 2012-09-27
Also published as: CH703576A2; CH703576A3; EP2689296B1; EP2689296A1

Abstract

The invention relates to a mechanical movement for a chronograph watch, comprising: a regulating body having an axle (2) and a spiral (1) mounted on said axle (2); and a starter (7) arranged in such a way as to impart a force in order to start the regulating body when the user starts the chronograph, the starter being arranged in such a way as to impart this force to a hub (3) mounted on the axle. Said solution is suitable for working with a regulating body that has a minimum of 3,600,000 alternations per hour.

Description

Mechanical movement for chronograph watch

Technical area

The present invention relates to a mechanical movement for a chronograph watch. The present invention also a watch

chronograph comprising such a movement and a method for accelerating and / or decelerating the regulating organ of the chronograph of a mechanical watch.

State of the art

Mechanical watches generally comprise a regulating member consisting of a flywheel called pendulum on the axis of which is fixed a spiral spring called spiral. In the prior art there are different types of balance wheels of various shapes; the most common balancers used in wristwatches consist of an annular mass, the serge, held by two or three arms. Other types of balances exist, for example balances devoid of serge and having only arms, as in FR330210A, or arms cooperating with flyweights made of high density metal to improve the weight / inertia of the balance, as described for example in CH698125.

Given the energy available, rockers usually have a high moment of inertia for a low mass; that is to say that their diameter is as large as the volume allows

provision, and that the mass is concentrated peripherally, for example in the serge or in other elements, for example flyweights. This moment of inertia can also be modified to adjust the watch, either manually with screws, or automatically in the case of bimetallic rockers that deform with the temperature. of the involuntary deformations of the pendulum, for example following

dilations, however, have the effect of disrupting the running of the watch.

In spite of the multitude of forms that the pendulums can take in the state of the art, the term pendulum can be defined by its function, unique or in any case principal, which is to increase the inertia of the regulating member to determine, together with the spiral spring, the oscillation frequency of the regulating member. Indeed, in the state of the art, the sprung balance oscillates around its equilibrium position at a frequency that depends mainly on the rigidity of the balance spring and the moment of inertia of the balance.

According to this definition, a rocker therefore constitutes a piece mounted on the balance shaft, pivotable with this axis and whose mass is distributed around the axis so as to give the regulating member a greater inertia in rotation. In other words, the word "pendulum" in this context indicates a piece whose main function, or even unique, is to accumulate at each oscillation a potential and kinetic energy which is higher, generally much higher, than that accumulated by the axis of the balance around which the oscillation takes place. For example, the potential and kinetic energy accumulated by a balance according to this definition is greater than or equal to at least 10 times that accumulated by the balance shaft, typically at least 1000 times greater.

The balance therefore has a moment of inertia which is greater than or equal to at least 10 times the moment of inertia of the axis, generally at least 1000 times greater.

The moment of inertia of a regulating member is determined by the set of rotating parts, including the balance shaft, the balance, the hub, the plate, the spiral, etc. In regulatory bodies

Conventional, this moment of inertia is, however, largely determined by the pendulum alone, which contributes at least 80% to the moment of total inertia of the rotating assembly. Preferably the moment of inertia of the pendulum represents at least 95% of the moment of inertia of the rotating assembly.

The rocker must therefore be distinguished from other elements such as the hub or the dowel plate, whose main function is not to increase the mass or the moment of inertia of the regulating member, whose moment of inertia is generally of the same order as the moment of the balance shaft, and which contribute only a small percentage to the moment of inertia of the rotating assembly.

In other words the balance serves as flywheel and fills the lack of energy stored in the hairspring during deformation. However the pendulum is source of many disturbances, due to inaccuracies of its inertia during its manufacture, dilations, etc.

A given pendulum coupled to a given spiral oscillates at a given frequency. The number of alternations per unit of time determines the temporal resolution of the regulator. For example, a mechanical watch displaying the seconds of the current time must comprise a regulating member performing at least 3,600 vibrations per hour. In practice, the usual regulating bodies perform 28,800 or sometimes 36,000 vibrations per hour, which makes it possible to measure the time with a resolution of 0.125 or 0.1 seconds, respectively.

By increasing the oscillation frequency, the temporal resolution is improved, allowing shorter time intervals to be counted. An improved temporal resolution is especially useful for chronographs, for which a time resolution of the hundredth of a second is sometimes desired. A high oscillation frequency, however, generates significant energy losses, especially at the exhaust, which reduces the power reserve of the watch. For this reason, the oscillation frequency chosen is usually a compromise between the chronograph resolution requirements and the desire to maintain as high a power reserve as possible for the display of the current time.

The usual chronograph watches take the energy necessary for the operation of the chronograph on the kinematic chain linking the barrel to the regulating organ and to the indicators of the watch. As a result, the watch is disturbed when the chronograph is started.

The patent application WO03 / 065130 in the name of TAG Heuer SA and whose content is incorporated by reference suggests a construction in which a basic movement intended for the display of the current time is provided with a first barrel and a a first regulating organ

performing 28,800 oscillations per hour, while a module

auxiliary chronograph is provided with a second barrel and a second regulating organ performing 360Ό00 oscillations per hour. This construction makes it possible to produce a chronograph watch capable of measuring the time with a resolution of one hundredth of a second, without affecting the power reserve of the basic movement used for the display of the current time. Moreover, the two cinematic chains being

the chronograph start does not affect the accuracy of the basic movement and the running of the watch. This solution was implemented in TAG Heuer's "Caliber 360" which demonstrated the technical feasibility of the solution. In this application, a launcher cooperating with a leaf spring provides the beam with a starting pulse to set it in motion. It also makes it possible to immobilize the balance by causing the stop of the chronograph.

The mechanical movements for a known chronograph watch would not be suitable for a regulating organ operating at 3'600'000 vibrations per hour, because of the high frequency of oscillation of the spiral.

Document CH 13140 describes a large seconds watch in the center provided with a small lever that makes it possible to stop and restart the pendulum of the watch. This lever has a rounded end which abuts against the axis of the pendulum thus causing the stop pendulum or imparting a pulse that restarts the watch. This system is not suitable for a high-frequency chronograph watch.

US352326 relates to a system for

stop / restart a regulating member constituted by a balance and a spiral, acting directly on the axis of the balance. This system comprises a sliding rod in two guides and having an end which comes into contact with the axis of the right-angle beam.

GB707759 discloses a movement for

Chronograph comprising an "L" -shaped start spring-wire, which gives an impulse to a pendulum.

The document CH31361 1 describes a time counter comprising a stop whip of a pendulum.

Brief summary of the invention

An object of the present invention is to provide a mechanical movement for an efficient chronograph watch and adapted to work with a regulating member at 3'600'000 vibrations per hour or more.

According to the invention, these objects are achieved in particular by means of a mechanical movement for a chronograph watch comprising the features of the main claim and a mechanical chronograph comprising such a mechanical movement as well as a method for accelerating and / or decelerating the chronograph regulator member of a mechanical watch having the features of claim 21. The mechanical movement for a chronograph watch according to the invention comprises:

a regulating member with an axis and a spiral mounted on this axis, this regulating member for regulating the chronograph operation; a launcher arranged to give a pulse to start the regulator when the user starts the chronograph;

characterized in that the launcher is arranged to give this pulse to the axis or to a hub mounted on this axis.

This solution has the advantage over the prior art of being adapted to a regulating member operating at 3'600'000 vibrations per hour.

This solution avoids giving a pulse directly on the pendulum. It is therefore also adapted to the regulating members without pendulum. In the case of a regulating member provided with a balance, it avoids the risk of modifying the balance of the balance.

This solution makes it possible to give a pulse on a hub whose outer diameter is greater than the diameter of the axis. The bearing surface between the launcher and the hub is therefore greater than the possible bearing surface between the launcher and the axis, which reduces the slip during launch. On the other hand, the tangential velocity at the surface of the hub is higher than the tangential velocity at the surface of the axis, and the torque necessary for the acceleration of the system consequently lower.

Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: Figure 1 illustrates a perspective view of a regulating member which belongs to the movement according to the invention.

Figure 2 illustrates a top view of a regulating member which belongs to the movement according to the invention. 3 illustrates a perspective view of the axis, the hub and the plate of a regulating member which belongs to the movement according to the invention.

FIG. 4 illustrates a launcher that belongs to the movement according to the invention. Figure 5 illustrates a top view of an anchor.

Figure 6 illustrates a bottom view of the anchor of Figure 5.

FIG. 7 illustrates a three-dimensional view of the regulator member according to the invention, the spring, the anchor and the anchor wheel.

Example (s) of embodiment of the invention

An embodiment of a regulating member is illustrated in FIGS. 1 and 2. This regulating member is in particular intended to serve as a regulator for the chronograph function of a mechanical chronograph; the same movement may comprise two regulating organs on the same plate, or on two separate plates, one of the regulating organs serving to regulate the running of the watch while the other organ

regulator, similar or similar to that described in this

request, serves to adjust the operation of the chronograph function. A separate barrel provides the energy required by each regulator member, which avoids disruptions in the operation of the watch when the chronograph is engaged. The power reserve of the second cylinder, which indicates the duration that can still be timed before having to recharge the second cylinder, is preferably indicated on the dial by means of a chronograph power reserve indicator. The power reserve of the first barrel charging the first regulator member used for the display of the current time is advantageously indicated separately on the dial by means of a power reserve indicator of the watch. The two barrels can preferably be loaded simultaneously by means of a common winding rod engaging on the two barrels and / or by means of a common oscillating mass. In another variant the first barrel is automatically reassembled and the second

manually. In a variant, the two barrels can be raised separately by means of two separate winding rods and / or oscillating masses. In another variant, one of the barrels (for example the chronograph cylinder) is loaded by the other cylinder manually or automatically remounted; the energy available is distributed between the two barrels.

The illustrated regulator comprises a hairspring 1 mounted with a ferrule 5 on a hairspring axis 2. The regulating member is devoid of balance. According to the example, the regulating organ of the chronograph is sized to oscillate at frequencies never reached before, preferably at a frequency of 3'600'000 vibrations per hour, or 500 Hz.

In order to reach these high frequencies, the regulating member comprises in particular an axis 2, which is intended to rotate between two non-represented bearings when the hairspring 1 is stretched and relaxed. A plate 4 mounted on this axis carries the plate pin 40 which collaborates with the horns 60, 65 and with the stinger 61 of an anchor 6 shown in FIGS. 5 and 6, similarly to the Swiss anchor escapements plus

conventional. In this context, the word "plate" therefore designates a part intended to be mounted on the axis of the regulating organ and which comprises an ankle, called a plateau pin, arranged to collaborate with the horns and with the stinger of an anchor .

The plate 4 is advantageously made of silicon or ceramic or other material with a lower density than that of the axis 2, in order to reduce its moment of inertia. It is

advantageously formed of two disks: the large plate 42 and the small plate 43, interconnected by a gun 45. The small plate may include a notch 430 for the dart. A simple tray, with a single disc, can also be used.

The axis 2 also carries a hub 3 driven or glued which serves to provide a bearing surface for the whip 72 of the launcher, described below in connection with Figure 4. The axis of the regulating member is thus accelerated by almost instantaneously when the push button 75 is engaged so as to communicate a pulse to the hub 3 through the blade 73, the column wheel 74 and the launcher 7. At the stop of the chronograph, the pressure of the whip 72 on the hub makes it possible to block the hub while maintaining the regulating organ of the chronograph and thus preserving the position of the chronograph hands.

In this context the expression "hub" is to be distinguished from the pendulum; a hub is a part intended to be mounted on the balance shaft, pivotable with this axis and cooperating with a spiral spring, which accumulates a potential energy and kinetics weak or comparable to that accumulated by the balance shaft. For example, the potential and kinetic energy accumulated by the hub is comparable to that accumulated by the balance shaft, or less than 10 times greater than the potential and kinetic energy of the axis, or smaller than that of the axis. 'axis. In the calculation of regulating members for conventional mechanical watches, the moment of inertia of the hub is generally neglected because it is significantly lower than the moment of inertia of the balance. For example, the moment of inertia of the hub is of the order of magnitude of 0.001 mg cm ² , that of the axis 0.010 mg cm ² and that of the balance 10 mg-cm ² .

The only function of the hub according to the invention is to provide a bearing surface for the launcher whip 7.

In a preferred embodiment the hub 3 is a separate part of the plate 4. In another variant, as will be seen pl away, the hub 3 and the plate 4 are integrated into a single element.

In another variant, it is the axis 2 which provides a bearing surface to the launcher whip: in this case the presence of the hub 3 is necessary.

Unlike a beam, the hub 3 is devoid of rays; its mass is thus concentrated near the center, so as to reduce its moment of inertia. The hub 3 is advantageously made of silicon or of another material with a lower density than that of the axis 2, in order to reduce its moment of inertia. In a variant, the hub is made of titanium and / or aluminum and / or an alloy containing at least one of these materials.

Blind openings 30 in a plane perpendicular to the axis 2 further lighten the hub 3. Blind or through openings in other direction, including holes through the hub parallel to the axis or according to any which direction, can also be used to lighten the hub 3. It is also possible to lighten the hub 3 by making it with a lighter core covered with a stronger coating on which the whip 72 of the launcher can give a pulse without deforming the hub 3. The openings in the hub and / or in the plate have the sole function of reducing their mass and therefore their moment of inertia. They do not serve as fixing means, and do not allow to receive adjustment screws or to avoid breaks in the hub or plate and are not used either to fix the hub or the plate to the axis.

In the same way, it is also possible to lighten the plate 4 by leaving through openings or blind, it is given a non-circular shape, in order to reduce its moment of inertia.

The regulating organ is devoid of a pendulum; its adjustment is done only with the raquetterie spiral 1, preferably by adjusting the length of the oscillating portion of the spiral by means of a screw perpendicular to the plate and to adjust the fixing point of the outer end of the spiral on platinum or on a bridge. This system allows a very precise adjustment of the length of the hairspring, but other known types of adjustment are applicable to the hairspring.

In a variant, the expression "regulating member without pendulum" indicates that the regulating member comprises a spring arranged to oscillate at high frequencies, for example at 50 Hz, or even at 500 Hz or more, and a solid balance shaft , that is to say an axis which determines, with a hub and / or plateau, the moment of inertia of the regulating member, no additional piece being added on this axis in order to increase the moment of inertia.

The diameter of the hub 3 is as small as possible, always in order to reduce its moment of inertia. In a preferred embodiment, the diameter of the hub 3 is between 1.5 and 10 times the maximum diameter of the axis 2, for example between 5 and 6 times the diameter of the axis 2. In the example shown, the outer diameter of the hub 3 is identical to the outer diameter of the plate 4. If a support surface for the larger launcher 7 is required, it will be possible to use a hub 3 slightly larger than the plate 4, its diameter not exceeding however, preferably not more than double the maximum diameter of the large plate 42.

Unlike a regulator comprising a balance, which brings a potential energy and kinematic substantially

greater than that of the axis 2, the potential and kinetic energy accumulated by the hub 3 is less than that which is accumulated by the axis 2 at each oscillation, preferably negligible compared to that of the axis 2.

The hub 3 can also be an integral part of the axis 2. In a variant, the hub 3 and the plate 4 are integrated in a single element, for example made by bar turning, which carries the plate pin 40 is on which s' supports the launcher 7. In another variant the ferrule is also integrated in this element. This element may advantageously be made of titanium and / or aluminum and / or an alloy containing at least one of these materials. The ferrule 5 maintains the inner end of the spring 1 on the axis 2. It is advantageously made in the form of a circular disc whose two or more segments are truncated to lighten it and reduce its momentum. inertia. A notch 50 in the side of the shell 5 is used to fix the spiral. The maximum diameter of the ferrule is preferably of the same order of magnitude as the maximum diameter of the plate and the hub. For example, the diameter of the hub 3 may be between 1 and 3 times the maximum diameter of the ferrule 5.

The hairspring 1 can be made of metal, preferably invar, silicon, diamond, corundum or any other suitable material. Advantageously, the hairspring is much stiffer than a hairspring

conventional, and therefore exerts a restoring torque to the rest position much larger than a conventional balance spring. The stiffness (or rigidity) of the hairspring is given by the formula:

C = M / (p C = stiffness constant of the spiral

M = return torque of the spiral,

φ = torsion angle.

High rigidity required for oscillation at 500 Hz can be achieved by combining at least two of the following:

- The number of turns is lower than in the spirals

traditional, so as to reduce the length of the vibrating part.

Advantageously, the spiral comprises less than 5 turns, for example 4.5, preferably 3 turns or less.

- The spiral is thicker than conventional spirals: for example its thickness is greater than 40 μηη, preferably greater than 50 μηη, for example 55 μηι.

- It is higher than the conventional spirals: for example its height is greater than 200 μηη, preferably greater than 215 μηη, for example 230 μηι.

It can be made of a more rigid material, preferably not sensitive to temperature variations.

- Ribs or a rectangular section can be used to stiffen it.

- A surface coating can be used to stiffen it.

- The spiral section may be non-constant along the spiral to stiffen it. The ratio (e ³ · /?) //, e being the thickness of the hairspring, h its height and

Its length is about 30 times greater than the same ratio of a conventional hairspring.

The spiral is advantageously constituted by a perfect Archimedean spiral, which is favorable to isochronism. Because of its stiffness and short length, it hardly deforms under the effect of gravity so that Philips end curves may not be necessary or even advantageous. Its rigidity also makes it less sensitive to disturbances due to magnetostriction. In addition, a rigid spring has the effect of increasing the frequency of oscillations and reducing their amplitude, which makes it possible to operate in a reduced oscillation range favorable to isochronism. Oscillations of reduced amplitude bring in other words a great precision to the watch. Since the oscillations of the hairspring are practically isochronous, the use of a coating, for example of silicon oxide, is no longer necessary.

The stiffness of the hairspring gives it an effective geometric stability: the hairspring therefore does not deform almost in different planes of space. Advantageously therefore this stiff spring has a greater static and dynamic stability compared to conventional spirals at 3-5 Hz. The stiffness of the hairspring also makes it non-self-starting, unlike conventional spring-balance regulators.

The oscillation frequency of conventional spiral-balance assemblies used in horology can be determined using the known formula

This frequency is thus inversely proportional to the square root of the moment of inertia / balance. In the state of the art, the moment of inertia / rotating parts of the regulating member is determined almost exclusively by the serge, which approximates a portion of hollow cylinder.

2) I = 1 _m ( _R ² _{+ r} ² )

From which we deduce:

- f Oscillation frequency [Hz]

- M Elastic torque of the spiral [N m]

- I moment of inertia of the balance [kg m ² ]

- R External diameter of the balance [m]

- r Internal diameter of the balance [m]

- h Thickness of the balance [m]

- P Specific mass of the balance [kg / m ³ ]

Equations 2) and 3) can not, however, be applied to the regulator of the invention, since this body is devoid of a pendulum. According to the invention, the regulating member is therefore dimensioned by integrating in the equation 1) above a moment of inertia / calculated by taking into account elements that are traditionally neglected in the prior art, in particular by integrating into the calculation of the moment of inertia / the moments of inertia of the axis 2, the plate 4, the hub 3 and the spiral 1 itself, which gives us an approximation for the frequency

oscillation.

The moment of inertia of the hairspring 1 however varies during each cycle when the hairspring is deformed, so that the application of the formula above gives only an approximation. In practice, an organ oscillating regulator at the desired frequency is obtained using the formula 1) above, / being approximated by adding the mass of inertia of all rotating parts. An adjustment is then obtained by successive approximations by modifying by means of the cock, a racket with a screw on the top, or another adjustment element not shown the length of the portion of the spiral 1 which can vibrate.

Prototypes were made with regulating devices capable of performing 500 oscillations per second, which makes it possible to measure timed durations with a resolution of one thousandth of a second. It is thus possible to achieve a mechanical chronograph at 500 Hz or thousandths of a second.

Figures 5 and 6 illustrate an embodiment of an exhaust anchor 6 can be used with such a regulating member. Compared to a conventional regulating member, the regulating member of the invention is characterized by substantially higher axis rotation speeds, for example 125 times greater. The impulse provided by the tooth of the anchor wheel (not shown) to the anchor 6 is therefore much shorter, the energy transmitted being on the other hand more important. This results in a much faster acceleration of the anchor 6: each time the anchor wheel transmits an impulse, the anchor switches almost instantly (in less than a thousandth of a second) between a position and the position opposite. The rotational speed of the teeth of the anchor wheel is such that the vanes can be removed and these teeth rely directly on the anchor inlet and outlet arms by projecting the entry and exit arms. the anchor at a distance as soon as they hit them; the arms do not have time to slip on the teeth of the anchor wheel. In other words the impulse response of the anchor is faster than those known and is of the annular type.

Consequently, according to an independent characteristic of the invention, and as illustrated in FIGS. 5 and 6, the vanes are removed and an annular contact, that is to say a point contact on a stop or distributed according to a set of coplanar points and whose contact norms compete, is done directly between the teeth of the anchor wheel and the arms 62, 63 of the anchor. The length of the contact between the anchor and the anchor wheel is advantageously less than one tenth of a millimeter, instead of one millimeter of the state of the art. Advantageously, the end of these arms has a rounded shape, for example involute or spiral or involute, this shape can be adjusted finely depending on the frequency of the spiral. In a variant, the teeth of the anchor wheel advantageously have a shape in complementary development, which makes it possible to better adapt to high frequencies and to ensure a perfectly punctual contact. These forms of anchor arms are advantageous for ensuring a fast and punctual contact between the anchor and the anchor wheel, without rebound and almost without slipping, even if, for example following an impact, the anchor or the wheel anchor are not exactly at the expected position during the impulse.

In order to be able to move quickly, the anchor 6 is preferably made of a material lighter than steel, for example silicon. Through holes 64 can lighten it even more. The stinger 61 is constituted by a bridge joining the two horns 60 and 65 but less thick than these horns and the rest of the anchor. The end of the stinger 61 opposite the center of the anchor is pointed to cooperate with the plateau pin 40.

The regulating member illustrated in the figures is advantageously used as an independent regulating member for a chronograph, in order to adjust the running of a chronograph hand in the center of the movement. For example, this regulator member may cause a hand in the center of the dial displaying thousandths of a second of a timed duration, and which travels 100 graduations on the periphery of the dial in a tenth of a second. In order to avoid any play and any loss of energy, the regulating member is preferably arranged in an unusual manner very close to the center of the watch movement, which makes it possible to drive the needle directly to the center, or in any case through a gear chain as short as possible, for example a chain gear having a single wheel to reverse the direction of rotation given by the anchor wheel. Preferably, the axis 2 of the hairspring is in an imaginary circle coaxial with the movement and of diameter less than 50% of the maximum external diameter of the movement, preferably less than 30% of the maximum external diameter of the movement, therefore very close to the center of the movement.

The accelerated chronograph hand can be deformed in the manner of a fishing rod during acceleration, which affects the reading accuracy during movement. In order to limit the extent of these deformations, the needle is advantageously ribbed and / or profiled to make it more rigid. The needle can also be replaced by a disc.

FIG. 4 illustrates the launcher mechanism which makes it possible to start the chronograph regulator member when the user presses the push-button 75 and then to block this regulator member when it is stopped. In the case of a regulating member according to the invention, the launcher comprises a flexible whip 72 which rests directly on the hub 3. The whip can comprise one or more parts and is more flexible than the rest of the launcher, so precisely whip the hub and start it instantly. The pressure of the push-button 75 is transmitted by the blade 73 to the column wheel 74, which suddenly releases the launcher 7 which is actuated by the launcher spring 71. The energy of this spring 71 is transmitted to the whip 72, which imparts a force to the hub 3 having a large tangential component, so as to accelerate suddenly the hub, the axis of the spiral and the possible balance, which allows to launch almost instantaneously the oscillator. At rest, when the user has pressed the push button 75, or an additional push button STOP not shown, the whip 72 presses on the hub 3 exerting a large radial force, in the position illustrated in Figure 4 , which blocks the hub axle instantly and energetically. The push button 75 in a preferred embodiment allows the user to perform both START and STOP functions. Another push button, not shown, allows the reset.

When the user actuates the STOP function, he allows the launcher to mount on one of the columns of the column wheel 74. When he actuates the STOP function, the spring of the launcher 71 allows the launcher 7 to fall in the space between two columns of the column wheel 74 and at the same time give a speed whip 72 which accelerates the hub. Advantageously, the blade 73 comprises a hook 730 which is intended to cooperate with the column wheel 74. In a variant, the blade and the hook constitute a single piece which is quite difficult to machine but which allows a reduction in the number of parts. In another variant the hook 730 is a separate part of the blade 73 and connected to it for example through a screw, which allows a better ease of machining.

FIG. 7 illustrates a three-dimensional view of the regulator member according to the invention, of the spring 1, of the anchor 6 and of the anchor wheel 8. The racket 9 cooperates with the screw 90 of fine adjustment of the length of the spring 1, with a tuning fork 10 and with a bridge 12 which is connected to the plate of the movement through the screw 14.

The regulating member of the invention is also distinguished from the regulating members of the prior art by the noise produced, which is different from the noise of the watch; because of the high oscillation frequencies, the usual ticking is replaced by a high-frequency hum, with a main harmonic at 500 Hz and secondary harmonics at multiples of 500 Hz. This very characteristic and very noticeable buzz allows the user to detect by ear that the

Chronograph is running, and thus avoid an unwanted discharge of the chronograph cylinder if the chronograph is started inadvertently or if we forget to stop it. The distinct and characteristic sound of the organ The chronograph regulator is therefore used as a signal indicating that the chronograph works. The watch case may advantageously comprise elements, for example vents or a resonance cage, in order to amplify this useful noise. In another variant the spiral of the regulating member according to the invention is replaced by a magnetic return member.

Reference numbers used in the figures

hairspring

Tuning fork

Bridge

Fixing screw from deck to deck

Axis of the spiral

Hub

Obviously in the hub

Tray

Plateau dowel

Large plateau

Small tray

Notch of the small plateau

gun

Ferrule

Notch of the ferrule

Anchor

Horn of entry

sting

^1st arm of the anchor

2 ^nd arm of the anchor

Holes crossing through the anchor

Horn output

Launcher

Launcher spring

Whip

Blade

Hook of the blade

Column wheel

Pushbutton

Anchor wheel

Racket

Adjustment screw end of the length

Claims

claims

1. Mechanical movement for a chronograph watch, comprising:

a regulating member with an axis (2) and a hairspring (1) mounted on said axis (2), said regulating member making it possible to regulate the movement of the

chronograph;

a hub (3) mounted on said axis;

a launcher (7) arranged to provide a pulse to start said regulator when the user starts the chronograph; characterized in that said launcher is arranged to give said pulse to said hub (3) mounted on said axis.

2. The movement according to claim 1, characterized in that the launcher (7) is arranged to transmit to said axis (2) or said hub (3) a force having a tangential component able to accelerate said organ

regulator.

3. The movement according to one of claims 1 or 2, characterized in that said launcher (7) is arranged to transmit to said axis (2) or said hub (3) a force having a radial component sufficient to instantly block said axis (2).

4. The movement according to one of claims 1 to 3, characterized in that the end of said launcher (7) is shaped whip (72) flexible.

5. The movement according to one of claims 1 to 4, characterized by a launcher spring (71) for actuating said launcher (7).

6. The movement according to one of claims 1 to 5, characterized by a column wheel (74) cooperating through a blade (73) with a push button (75).

7. The movement according to one of claims 1 to 6, characterized in that said hub (3) is provided with non-functional openings (30) to reduce the moment of inertia of said hub (3).

8. The movement according to one of claims 1 to 7, said axis (2) being metal and said hub (3) being silicon or ceramic.

9. The movement according to one of claims 1 to 8, comprising a plate (4) mounted on said axis, and a plateau pin (40) mounted on said plate (4).

10. The movement according to one of claims 1 to 9, said launcher (7) being arranged to exert pressure on said hub (3) when the chronograph is stopped, so as to block said axis (2) of said regulator member.

1. The movement according to one of claims 1 to 10, said hub (3) consisting of a disk mounted on said axis (2).

12. The movement according to one of claims 7 to 11, said hub (3) being provided with several said openings (30) blind in a direction perpendicular to said axis (2), to reduce the moment of inertia of said hub (3).

13. The movement according to one of claims 1 to 12, said regulator member being devoid of pendulum.

14. The movement according to one of claims 1 to 13, said hub (3) being made of a material density lower than that of said axis (2).

15. The movement according to one of claims 1 to 14, the diameter of said hub (3) being between 1.5 and 10 times the maximum diameter of said axis (2).

16. The movement according to one of claims 1 to 15, said spiral (1) having five turns or less.

17. The movement according to one of claims 4 to 16, said whip (72) comprising one or more parts.

18. The movement according to one of claims 6 to 17, said blade (73) comprising a hook (730).

The movement of claim 18, said hook (730) being a separate piece from said blade (73).

20. Mechanical chronograph comprising a first mechanical movement according to one of claims 1 to 19 for measuring durations, and a second mechanical movement comprising a regulating member oscillating more slowly for the display of the current time.

21. A method for accelerating and / or decelerating the regulating organ of the chronograph of a mechanical watch comprising

- pressing a push button (75) with the pressure of a finger;

- transmitting this pressure by a blade (73) to the column wheel (74);

releasing a launcher (7) actuated by a launcher spring (71);

direct contact between the launcher and a hub (3) on this axis (2);

- acceleration / deceleration of the regulating organ.