Clockwork movement for wrist watch, has pawl arranged to urge tooth of toothing of column-wheel when pushbutton is moved to active position and disengage toothing sliding over top of tooth when button returns to rest position

CH 705.848 A2

Description FIELD OF the INVENTION

The present invention relates to a clock making movement comprising a mechanism of stop watch at three times arranged to order a needle of stop watch and at least a needle of meter so as to start them, to stop them, then to quickly bring back them to their starting point, at will, by successive pressures on the same push-button. The present invention relates to such a clock making movement more specifically comprising a wheel with columns and in which the successive pressures on the push-button cause to gradually increment the angular position of the wheel with columns.

FORMER ART

One knows clock making movements which correspond to the definition above. The document of patent WO 03/040 835 in particular, described a movement of watch provided with a stop watch in conformity with the preamble to annexed claim 1. The fig. 1 and 2 annexed reproduce the fig. 3 and 8 of this former document. These fig. are sights side melts of this clock making movement of former art. The fig. 1 shows the movement with the mechanism of stop watch in home position, and the fig. 2 is a sight similar showing the restoring of the mechanism of stop watch.

One represented on the fig. 1 and 2 a rocker of order 1 which is assembled swivelling around a tenon screwed in the bridge of barrel (the tenon and the bridge of barrel are not represented on the fig., but the fulcrum pin is indicated by the sign “+”). A lb end of the rocker is intended to be connected to a single push rod (not represented).

The other end of the rocker of order ends in a pawl 2 in the shape of hook which is designed to cooperate with teeth ratchet 4a of the wheel with columns 4. A first spring (not represented) is designed to point out the rocker of order 1 in the home position represented in the fig. 1. A second spring (not represented) is designed to point out constantly pawl 2 against teeth ratchet 4a. Finally, a spring saltire 3 is also in catch with teeth ratchet of the wheel with columns.

The operation of the mechanism of push rod designed to actuate manually the wheel with columns 4 now will be described. As one I' already said, the lb end of rocker 1 is connected to the single push rod. When a user presses on the button of the push rod, it pushes back the lb end rocker of order in direction of the center of the movement. The rocker being swivelled in its center, the displacement of the lb end in direction of the center of the movement is accompanied by a displacement in opposite direction of pawl 2. While moving, the pawl hangs a tooth of the ratchet 4a and involves this tooth in direction of the outside of the movement. By doing this, it makes turn of a step the wheel to columns.

When the user slackens his pressure on the push rod, the rocker is brought back in home position by the first return spring. During this movement, pawl 2 in the shape of hook slips on the tilted one of a tooth of the ratchet 4a without making turn the wheel to columns.

While still referring to the fig. 1 and 2, one can observe that the rocker of order 1 takes a considerable place with the periphery of the movement. Document WO 03/040835 explains why the shape of the mechanism of stop watch represented enables him to be associated with a clock making movement with noncircular form. To produce a round watch which integrates this kind of mechanism of stop watch, the clock and watch makers do not have often an other recourse only to use a box of watch larger than the movement, they insert a circle of enlarging designed to center the movement in the box of round form. A disadvantage of this solution is that it only makes it possible to produce watch-stop watch of relatively great dimensions.

IN SHORT INVENTION EXPOSES

A goal of this invention is to provide a mechanism to extremely compact push rod and allowing the use of a low-size push-button with a race limited to order the wheel with column of the mechanism of the stop watch of a clock making movement. The present invention achieves this goal by providing a clock making movement in conformity with annexed claim 1.

BREVES DESCRIPTION OF THE FIGURES

Other characteristics and advantages of this invention will appear with the reading of the description which will follow, only given as nonrestrictive example, and made in reference to the annexed drawings in which:

- the fig. 1 - the fig. 2 - the fig. 3 is a sight in plan of top of a mechanism of stop watch at three times of art former at rest; is a sight similar to the fig. 1 of the mechanism of stop watch during the restoring; is a sight in plan of a mechanism of stop watch corresponding to a particular mode of realization of this invention, the mechanism of stop watch being put at zero, ready to start; CH 705.848 A2

- the fig. 4 - the fig.

- the fig. 6 - the fig. 7 - the fig. 8 - fig. the 9 - the fig. 10a and 10b - fig. 11 - the fig. 12 is a sight in plan of the mechanism of stop watch of the fig. 3 at the moment of the starting; is a sight in plan of the mechanism of stop watch of the fig. 3 and 4 during walk; is a sight in plan of the mechanism of stop watch of the fig. 3 to 5, moment of the stop; is a sight in plan of the mechanism of stop watch of the fig. 3 to 6, stop; is a sight in plan of the mechanism of stop watch of the fig. 3 to 7, moment of the restoring; is a partial sight in plan which corresponds to the superposition of two instantaneous. These two instantaneous respectively illustrates the home position and the active position of the mechanism with push rod; are sights of a strip in the shape of flag belonging to the mechanism with push rod; is a sight in plan of top of the wheel with columns of the mechanism of stop watch of the fig. 3 à8; is a sight in prospect for the wheel with columns for the fig. 11.

DETAILED DESCRIPTION Of a MODE OF REALIZATION

While referring first of all to the fig. 11 and 12 which represent a wheel with columns 40 adapted to be integrated in a clock making movement in conformity with the present invention, one can see that the latter is primarily made of a ratchet 42 and four columns 44 distributed in a regular way to the circumference of the ratchet. The wheel with columns still comprises a hub 46 designed to be gone up swivelling around an axis of the mechanism of stop watch (not represented on the fig. 11 and 12). The fig. 11 still contains an arrow referred R and intended to indicate the direction of rotation of the wheel to columns 40. It will be noted that, in this example, it is about the time direction.

In the example represented, the wheel with columns comprises four more arms 48 which respectively connect four columns 44 to hub 46 of the wheel. Columns 44, arms 48 and hub 46 thus form a superstructure which has a symmetry of rotation of order 4. Ratchet 42, as for him, account 12 spaced teeth of 30° one of the other. The specialist of the profession will thus understand that the wheel with columns of this example is well a wheel with columns with 12/4 of time (3 times).

The sight in prospect for the fig. 12 makes it possible to visualize well the hub 46 and the arms 48 which connect the columns to the hub. The presence of the arms and the hub makes it possible to in general rigidify the structure of the wheel, and the columns in particular. It will be understood that a more rigid wheel with columns allows an operation with a particularly high level of precision. One can still observe that the width of the arms at their narrowest point is considerably lower than the width of the columns (one defines here the width of a column as the distance separating the leading edge from the trailing edge of this column). According to the invention, the width of arms 48 is lower than half of the width of columns 44. In this example, the width of an arm is even about the third of the width of a column. This characteristic of the invention makes it possible to arrange vacuums 45 in the superstructure of the wheel with columns. These vacuums are necessary to allow the nozzles various rockers to sufficiently deeply plunge between the columns.

One can still see on the fig. 12 that hub 46 and arms 48 have a height lower than that of columns 44. The height of the arms preferably will lie between 20% and 60% height of the columns. An advantage of this last characteristic is that it makes it possible to still lengthen the race of the nozzle of a lever in diving as in lifting, in so far as this lever is assembled to sufficiently high allow the passage of the nozzle the top of arms 48 of the wheel with columns. Preferably, one entirely manufactures the wheel with columns on a screw cutting machine. A manufacture without recovery on a screw cutting machine makes it possible to give at piece-rates a remarkable precision.

The fig. 11 shows clearly the profile of columns 40. One can observe that the profile of the columns corresponds in a general way to a warped ellipse, or more precisely perhaps, with the profile of a wing of plane. One will thus indicate by leading edge the side before columns (while referring within the meaning of rotation of the wheel with columns), and by trailing edge the back edge of the columns. The columns also present an outside (turned towards the external one of the wheel with columns) and an interior face (turned towards hub 46). The outside and the interior face meet on the level of the leading edge and the level of the trailing edge. One can observe that with regard to their outside, the profile of the columns draws an appreciably concentric arc of circle to the wheel with columns. While to the level of the interior face, the profile of the columns presents a larger radius of curvature in the area of the trailing edge than in the area of the leading edge (as it is the case with a traditional wing of plane).

On the fig. 11, one indicated by O the angle which the interior face with the outside of a column in the area of the leading edge forms, and by iß the angle that the interior face with the outside of a column in the area of the trailing edge makes. One can see on the fig. 11 that the two angles O and iß actually are very rounded. The fact that the angle O is very CH 705.848 A2

rounded present the advantage of facilitating the progression of the nozzle of a lever cooperating with the column during the operation of the mechanism of stop watch. Concerning rangle iß, the fact that rangle is round does not have really a technical effect, and according to an alternative, rangle iß could be sharp. In the illustrated example, the angles and iß are worth respectively 58 degrees and 31 degrees. According to various alternatives of realization, rangle can vary, but it is preferably included/understood enters and 65 degrees. The angle iß, as for him, depends on the number of columns which the wheel with columns comprises, and it will be preferably smaller when the columns are more numerous. However, rangle iß will preferably be included/understood enters and 35 degrees.

Finally, the width of a column 44 depends naturally on the number of columns which the wheel with columns 40 comprises. However, according to rinvention, the columns of the wheel with columns are broader than the openings arranged between the columns.

The fig. 3 to 8 are sights side melts of a clock making movement according to a particular mode of realization of this invention. The clock making movement represented is designed to be integrated into a wrist watch. Under these conditions, the crown-push rod which is represented in top on the fig., would be located in fact at three hours if one looked at the side dial of a wrist watch containing the movement. It will thus be understood that, since the fig. 3 to 8 are sights on the side melts, the position “midday” of the watch is side right-hand side of the fig., and the turn of hours extends anticlockwise on the figures.

The fig. 3 to 8 represent the mechanism of stop watch with various phases of a complete cycle of its operation. In addition to the wheel with columns 40 already described, the mechanism of stop watch represented includes/understands in particular a wheel of stop watch 1, a rocker of clutch 4 presenting a nozzle designed to cooperate with the wheel with columns, a pinion oscillating 2 swivelled on a clutch lever 3, and two springs (referred respectively 5a and 5b). The clutch lever is arranged to swivel in direction or rautre so that it causes alternatively the release or re-engagement of the teeth of the pinion oscillating 2 of with that of the wheel of stop watch 1. The swivelling of the clutch lever 3 has as a function to allow rarrêt and the restarting of the stop watch. Indeed, the pinion oscillating 2 is actuated permanently by the mobile of second of the wheel of the movement (not represented). Under these conditions, when the wheel of stop watch is in catch with pinion 2, eile is involved, and when the oscillating pinion is disengaged of its teeth, the wheel of stop watch is disconnected.

The spring 5a has as a function to point out the clutch lever, and the oscillating pinion which it carries, against the wheel of stop watch. As for the spring 5b, it is arranged to recall the nozzle of the rocker of clutch against the wheel to columns. One can see moreover on the fig. that the rocker of clutch 4 carries, with rextremity opposed to the nozzle, a pin 6 designed to cooperate with a corresponding end of the clutch lever 3. One can see first of all that when the nozzle of rocker 4 is lowered between two columns, as represented on the fig. 4 and 5 in particular, pin 6 is isolated clutch lever. Under these conditions, nothing is opposed so that the spring 5a engages the pinion oscillating 2 with the teeth of the wheel of stop watch 1. Contrary, when the nozzle of the rocker of clutch is raised by a column of the wheel with columns, as represented with the fig. 3 in particular, pin 6 forces the clutch lever 3 to swivel, which causes to draw aside the pinion oscillating 2 of the teeth of the wheel of stop watch. It is thus the wheel with columns 40 which orders the clutch and the disengaging of the wheel of stop watch 1.

The mechanism of stop watch represented includes/understands a wheel of meter of minutes 15 and one more intermediate gear 12. The wheel of meter 15 is pulled by the wheel of stop watch 1 by rintermédiaire of wheel 12.

One can still see that the wheel axle of stop watch is that of the wheel of meter of the minutes change all two a heart of handing-over to zero (referred respectively 7 and 17). A hammer with two tilted is designed to cooperate with the two hearts. This hammer is made of a rocker of restoring 10 and of a mobile breakdown in the shape of swing bar 9.

The mobile breakdown is articulated on an end of rocker 10 and eile presents two tilted 8a, 8b which is designed to cooperate each one with one of two hearts 7,17. In a known way in oneself, the rocker of restoring 10 is arranged to swivel, either in a direction to lower the hammer against the hearts, or in rautre direction to raise the hammer. A spring 19 is still arranged to point out the hammer against hearts 7,17 in home position. Lastly, it is also the wheel with columns 40 which orders the swing of the hammer.

The mechanism of stop watch of this example still includes/understands a brake consisted a rocker of brake whose rune of the ends carries a shoe 32 designed to immobilize the wheel of stop watch 1 while acting on its circumference. In a conventional way, the rocker of brake 30 is arranged to swivel alternatively between a raised position where shoe 32 is held isolated wheel of stop watch is a lowered position where the shoe blocks the wheel of stop watch. A spring (not represented) is still arranged to point out shoe 32 against the wheel of stop watch in home position. In addition, it is also the wheel with columns 40 which orders the swivelling of the rocker of brake the mechanism of stop watch of the invention still comprises a mechanism to order the wheel with coIonnes. This mechanism which is the object of this invention is a mechanism with push rod. In a traditional way, the mechanism with push rod is arranged to make gradually increment the angular position of the wheel with columns 40, Iorsqu' a user actuates button 67 of the push rod in a repeated way. In addition, the wheel with columns 40 is under the action of a saltire of wheel with columns (referred 50 in the fig. 3 and 6) which presses against the teeth of the ratchet (referred 42) so as to maintain the wheel with columns in a stable position.

CH 705.848 A2

The push rod of crown-push rod 65 is arranged to move axially in the plan of the Iorsqu' movement a user actuates the push rod while pressing on button 67 of the crown push rod 65. The push rod passes thus from a home position (illustrated in the fig. 3 in particular) to an active position (illustrated in the fig. 4 in particular).

The mechanism which, in the example represented, connects button 67 of crown-push rod 65 to the wheel with columns includes/understands a pawl 52, a spring of pawl 54, a rocker of order 56, an intermediate lever of order 58 and one spring of order 60. As one I' already said, in this example, crown-push rod 65 is laid out with the periphery of the movement, at “3 hours”. The crown-push rod is associated with a stem of reassembly and setting per hour (referred 71 with the fig. 9) which extends in direction from the center from the movement. The intermediate lever 58 is assembled on a pivot 59 (called “second pivot hereafter”) which is fixed on the frame, at “4 hours”, near to the periphery of the movement. In this example, the form of the movement is round. Thus, the slightly bent shape of lever 58 enables him to extend appreciably along the periphery from the movement in the interval between “4 to 2 a.m.”. The intermediate lever increases to 3 a.m. a strip 62 which is turned in direction of the crown-push rod. This strip is bent according to an angle of approximately 90° in direction on the side dial of the movement. The strip thus forms a flag which makes roughly vis-a-vis the crown-push rod. As one will see it more in detail further, the push rod comprises a bearing surface 69 which is arranged to come to press against the flag so as to actuate the intermediate lever of the control drive when the push-button is actuated.

The rocker of order 56 is assembled on a first pivot 55 which is fixed on the frame at 1 a.m. One can see on the fig. 3 in particular that the slightly bent shape of the rocker of order enables him to extend appreciably along the periphery from the movement until proximity from the crown-push rod. Thus, in short, the rocker of order 56 and the intermediate lever 58 are swivel on both sides and remote of crown-push rod 65. They extend to the meeting one from the other starting from their respective pivot 55,59, appreciably along the periphery of the movement.

One can still see on the fig. which the loose lead of rocker 56 presents a projecting member made up, in this example, by a tenon stages 57. The projecting member is arranged to cooperate with the distal end of the intermediate lever 58.

More precisely, as illustrated on the fig. 3 to 9, the distal portion of lever 58 is arranged to come in support against the tenon stages 57.

The spring of order 60 is arranged to cooperate with the rocker of order 56 so as to point out the loose lead of the latter in direction of the periphery of the movement. One will include/understand moreover than because of the presence of tenon 57, the action of spring 60 also causes to recall lever 58 towards the outside of the movement.

Conversely, Iorsqu' a user makes swivel lever 58 while pressing on push rod 67, the distal end of this lever comes to push tenon 57, thus making swivel the rocker of order 56. By comparing the fig. 3 and 4 for example, one can see moreover that the simultaneous swivelling of the intermediate lever 58 and the rocker of order 56 is accompanied by a slip of tenon 57 against the distal portion of the intermediate lever. It will be understood that because of this slip, when the mechanism with push rod pass from the home position to the active position, the arm of lever between pivot 59 of the intermediate lever and tenon 57 is shortened.

The fig. 10a and 10b illustrate strip 62 in the shape of flag which the intermediate lever 58 carries. The fig. 10a is the superposition of two side views corresponding to two instantaneous of the strip respectively in home position and active position of the mechanism with push rod. The fig. 10b is a front view of strip 62 since the side of the crown-push rod. One sees in particular on this fig. that a release is arranged in the left part of the flag. This release is positioned in the axis of the stem of reassembly and setting per hour 71, so that it allows the passage of this stem. In addition, it is seen that the strip has a narrow distal part 72 (on the right on the fig. 10b) which is designed to extend on the side from stem 71, on the side of pivot 59 of this one. Side of the release, the strip forms a shoulder 74. This shoulder occupies space between stem 71 and the principal plan of the intermediate lever 58.

Like the fig. 10a, the fig. 9 is the superposition of two instantaneous. These two instantaneous respectively illustrates the home position and the active position of the intermediate lever 58 and tenon 57. It will be understood that the fig. 9 is a sight of the movement since the side bridge, the plan of the drawing being parallel to that of the movement. The flag formed by strip 62 thus extends in a plan perpendicular to that from the drawing. The two lines of and D " on the drawing are respectively the traces of the plan of the flag in the home position and the active position of the mechanism with push rod.

One sees that in fact an angle there with the plan of the bearing surface 69, whereas D” forms an angle 8 with this plan. The angles there and 8 are of opposite sign.

One can see on the fig. 9 that, as one I' already said, strip 62 is roughly in the axis of crown-push rod 65. When the push rod is in home position, the intermediate lever 58 is swivelled in direction of the outside of the movement. In this position, the plan of the flag is not completely parallel to the bearing surface 69 of the push rod as the angle testifies some enters there the trace of and the plan of the bearing surface. Under these conditions, when the pushbutton goes from the home position to the active position, the bearing surface 69 starts by supporting against the edge of the strip close to shoulder 74. From this moment, the pressure of the bearing surface on the strip causes to make swivel the intermediate lever 58 and thus to make also swivel the plan of the flag. It is followed from there that the angle between the plan of the flag and the plan of the bearing surface changes soon sign. At the same time, the zone of contact between the bearing surface and the strip move towards the narrow distal part 72 of the strip. By referring CH 705.848 A2

still with the figure, one will understand that the arm of lever between second pivot 59 and the distal part 72 is shorter than the arm of lever between pivot 59 and shoulder 74. Thus, when the mechanism with push rod pass from the home position to the active position, the arm of lever between pivot 59 of the intermediate lever and the zone of contact with the bearing surface 69 of the push rod is shortened. This last shortening has the advantage of compensating for the simultaneous shortening of the arm of lever between pivot 59 and tenon 57. Thus, the variation of the report/ratio of lever of the intermediate lever 58 at the time of the passage of the home position to the active position is at least partially compensated.

In a known way in oneself, the loose lead of the rocker of order 56 carries the pawl of rocker of order (referred 52). Pawl 52 is swivelled freely on the end of the rocker and he is recalled against teeth ratchet 42 of the wheel to columns by the spring of pawl 54. Pawl 52 is thus arranged to cooperate with the teeth of ratchet 42, and when under the effect of a pressure on the push rod, the end of the rocker of order 56 is brought to swivel in direction of the center of the movement, pawl 52 accompanies this movement by pushing a tooth by the ratchet towards the center of the movement. Thus, in a usual way, each pressure on the push rod advances the wheel with columns of the value of a tooth of the ratchet. Then, as soon as that the pressure on the push rod is slackened, the spring of order makes take again their home position to rocker 56 and lever 58. Pawl 52 retrogresses also while désengageant ratchet by slip on the tilted one of a tooth. The pawl is thus ready to actuate the following tooth, at the time of the next pressure on the push rod. It will be understood what precedes that, in this example, the rocker of order 56 constitutes with lever of the 2nd kind (in other words “inter-resistant”), and that pawl 52 actuates the wheel with columns by pushing back the teeth of ratchet 42. This fitting differs from that of the traditional mechanisms with push rod, in which, the rocker of order behaves like a lever of the 1st kind (in other words “inter-support”), and in which the pawl with the shape of a hook which actuates the wheel with columns by drawing a tooth from the ratchet in direction of the outside of the movement (as illustrated in the fig. 1 and 2 representative a mechanism of stop watch of former art). An advantage of using a lever of the 2nd kind, which carries a pawl arranged to push the teeth of the ratchet, is that it makes it possible to reduce the place occupied by the mechanism of stop watch.

In a traditional way, in this example, It is necessary to exert three pressures on the push rod, so that a column takes the place of the preceding one, which corresponds to the three functions of the stop watch: the departure, the stop, and restoring. The fig. 3 shows the mechanism of stop watch to the stop, after being given to zero. All the elements of the mechanism of stop watch are stopped except for the pinion oscillating 2 which is actuated permanently by the wheel of the movement of the watch (the direction of rotation of the oscillating pinion is indicated by the arrow).

The fig. 4 illustrates the moment of the starting of the mechanism of stop watch. Button 67 of the crown-push rod is inserted and the intermediate lever 58 as well as the rocker of order 56 have swivel in direction of the center of the movement by involving pawl 52. This displacement of the pawl advances the wheel with columns 40 of 30° clockwise. The rotation of 30° of the wheel with columns causes, on the one hand, to make raise the nozzle of the rocker of restoring 10, making it swivel so as to raise the hammer and to release hearts 7,17. In addition, the rotation of the wheel with columns also causes to make plunge the nozzle of the rocker of clutch 4 in space between two columns (referred 44 on the fig. 9 and 10). Like one ruffle considering higher, while thus allowing the rocker of clutch to swivel under the action of spring 5, the incrementing of the wheel with columns also leads the teeth of the pinion oscillating to couple with that of the wheel of stop watch 1. Finally, the rotation of 30°, does not have an effect on the brake whose nozzle remains raised.

The fig. 5 shows the mechanism of stop watch moving. Button 67 of crown-push rod 65 returned to its home position, like are also the intermediate lever 58 and the rocker of order 56. Pawl 52 also returned behind, and is ready to actuate the following tooth when the push rod is actuated again. The wheel of stop watch 1, the intermediate gear 12 and coil it meter of minutes 15 are rotated by the pinion oscillating 2 in the direction indicated by the arrows on the figure.

The fig. 6 illustrates the moment of the stopping of the mechanism of stop watch. Following a new actuation of the crown-push rod, push-button 67 is inserted and the intermediate lever 58 as well as the rocker of order 56 have again swivel in direction of the center of the movement by involving pawl 52 and while making turn once again the wheel to columns of 30°. This new incrementing of the wheel with columns causes, on the one hand, to make raise the nozzle of the rocker of clutch 4, leading the pinion oscillating 2 to disengage wheel of stop watch 1.

In addition, the rotation of the wheel with columns also causes to make plunge the nozzle of the rocker of brake 30 in space between two columns 44 while making swivel the rocker. Like one ruffle considering higher, swivelling of the rocker made drop shoe 32 against the wheel stop watch 1, so that the shoe blocks the wheel of stop watch.

The fig. 7 shows the mechanism of stopped stop watch. The button of crown-push rod 65 returned to its home position, like are also the intermediate lever 58 and the rocker of order 56. Pawl 52 also returned behind, and is ready to actuate the following tooth when the push rod is actuated again.

Shoe 32 of the rocker of brake 30 retains the wheel of stop watch 1, and meter of minutes 15 coils it, in the position in which the mechanism of stop watch was stopped, allowing the reading of the time passed between the starting and the stopping of the mechanism of stop watch.

The fig. 8 illustrates the moment of the restoring of the mechanism of stop watch. Following a new actuation of the crown-push rod, button 67 is inserted and the intermediate lever 58 as well as the rocker of order 56 have again swivel in direction of the center of the movement by involving pawl 52 and by incrementing once again CH 705.848 A2

coil with columns of 30° This new displacement of the wheel with columns causes, on the one hand, to make raise the nozzle of the rocker of brake 30, leading shoe 32 to deviate from the wheel of stop watch 1. In addition, the rotation of the wheel with columns also causes to make plunge the nozzle of the rocker of restoring 10 in space between two columns 44, thus making swivel the rocker. This swivelling of the rocker causes to lower the two tilted ones Its and Sb of the hammer respectively against two hearts 7,17, of kind to bring back the wheel of stop watch 1 and coils it meter of minutes 15 with their respective starting positions.

While referring still with fig. 3 to 8, one will note that, if one compares the nozzle of the rocker of clutch 4 and that of the rocker of restoring 10 with the nozzles which are represented in the fig. 2, One notes immediately who the nozzles of the rockers of the movement of stop watch in conformity with the present invention can be more frayed much than those of former art. An advantage of this characteristic is that a frayed nozzle (whose point forms an angle lower than 40°; preferably an angle lower than 30°), makes it possible the rockers of the mechanism of stop watch of this example to drop even in the relatively narrow space consisted the interstice between two columns of the wheel with columns illustrated with the fig. 10 for example. As a corollary, it will be also understood that the use of nozzles frayed like those of the rockers of the mechanism of stop watch of this example, requires in return to have broader columns to avoid than the nozzles do not drop ill-advisedly.