EP2228692A1 - Column wheel for a chronograph, chronograph and chronograph timepiece comprising such a wheel - Google Patents

Abstract

The wheel (1) has a ratchet (2) with teeth whose shape defines a rotational axis for the wheel. A superstructure is coaxial to the wheel, and has rotation symmetry of around n greater than/equal to 3. A peripheral portion of the superstructure defines n columns (10) parallel to the axis and arranged along an edge of the ratchet. Each column has an outer portion whose cross-section is asymmetrical and in the form of a truncated triangle. An angle between a front side i.e. leading edge, and a base is lower than an angle between the base and a rear side i.e. trailing edge, of the triangle. An independent claim is also included for a control mechanism for a chronograph, comprising a pivoting lever.

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a chronograph column wheel comprising columns whose shape is optimized. It also relates to a chronograph control mechanism and a chronograph watch comprising such a column wheel.

STATE OF THE PRIOR ART

In a chronograph watch, in order to control and manage the various functions of the chronograph, it is known to use a column wheel. The columns of the column wheel conventionally have a cross section often substantially in the form of a truncated triangle (see FIG. figure 1 ). This type of shape makes it possible to manufacture the wheel and the columns in a simple and inexpensive way. However, the various levers subjected to the action of the columns are subjected to efforts sometimes too important, thus increasing the levels of friction and wear. In addition, the level of precision, when implementing the various functions of the chronograph, is not always optimal.

SUMMARY OF THE INVENTION

An object of the present invention is to overcome the aforementioned drawbacks of the prior art by providing a column wheel for a better distribution of forces on the levers and a higher level of precision in the management of chronograph functions. She achieved by providing a column wheel according to the appended claim 1.

It will be understood that it is with respect to the direction of rotation of the column wheel that a front side and a rear side of the truncated triangle shaped cross-section are defined.

The characteristics of the invention make it possible to optimize the general mechanical characteristics of the levers cooperating with the columns: for example, a reduction in friction, wear and energy losses, and a better accuracy of the arrangements of parts and functions are obtained. resulting, etc. This results in better management of the chronograph functions.

The geometry of the columns makes it possible to precisely define the direction of the vectors of force necessary for the lifting of the levers. This results in a reduction of the forces involved, a better performance, a decrease in wear and increased control of the force to exert on the command "start / stop".

According to an advantageous embodiment, the base is convex so as to be substantially parallel to the circumference of the column wheel.

The angle α is advantageously less than the angle θ of at least 10% and preferably at least 20%. Moreover, the angle α is preferably between 50 and 53 degrees. It will be understood on the one hand that by choosing a sufficiently salient angle α (α <53 °) it is possible to maximize the length of the spout stroke, which allows either to increase the lever lift angle or to increase the length of the lever arm while keeping the same lifting angle. On the other hand, if the angle a is too salient (α <50 °), the efforts concentrate on the angle α, which can lead to an undesirable increase in the losses and the force required to actuate a ordered.

According to another advantageous embodiment, the superstructure of the column wheel comprises a hub connected to the columns by arms so as to strengthen the columns.

According to yet another advantageous embodiment, the hub and the arms have a height of between 10% and 50% of the height of the columns.

The invention also provides a chronograph control mechanism comprising a column wheel as previously described and at least one rocker lever whose beak is likely to cooperate with the columns of the column wheel.

The invention furthermore provides a chronograph watch comprising a column wheel as previously described and at least one rocking lever whose beak is capable of cooperating with the columns of the column wheel. The lever may for example be a clutch rocker, a hammer or a blocker.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 montre une vue en perspective d'une roue à colonnes de type connu ;
• la figure 2 est une vue schématique de dessus en section transversale d'une colonne d'une roue à colonnes selon un mode de réalisation particulier de la présente invention ;
• la figure 3 est une vue en perspective de la roue à colonne de la figure 2 ;
• la figure 4 est une vue de dessus de la roue à colonnes des figures 2 et 3 ;
• la figure 5 est une vue côté rouage présentant un exemple d'intégration dans une montre-chronographe d'une roue à colonne selon un mode de réalisation particulier de la présente invention ;
• les figures 6a et 7 à 12 correspondent à sept instantanés successifs décrivant la fonction « start », c'est-à-dire la séquence durant laquelle une pression de l'usager sur un poussoir fait avancer d'un pas de 30° la roue à colonnes montée dans une montre-chronographe. L'avance de la roue à colonnes faisant se soulever un marteau pour libérer les coeurs du chronographe et en actionnant également la bascule d'embrayage pour faire démarrer l'aiguille de chronographe. Les sept « instantanés » sont pris tous les 5°;
• la figure 6b décrit le même instant que la figure 6a, mais montre l'ensemble du mécanisme.

Other features and advantages of the present invention will appear on reading the following description, given solely by way of non-limiting example, and with reference to the appended drawings in which:

• the figure 1 shows a perspective view of a known type column wheel;
• the figure 2 is a schematic top view in cross section of a column wheel column according to a particular embodiment of the present invention;
• the figure 3 is a perspective view of the column wheel of the figure 2 ;
• the figure 4 is a top view of the column wheel of the figures 2 and 3 ;
• the figure 5 is a train-side view showing an example of integration in a chronograph watch of a column wheel according to a particular embodiment of the present invention;
• the Figures 6a and 7 to 12 correspond to seven successive snapshots describing the function "start", that is to say the sequence during which a pressure of the user on a pusher advances by a step of 30 ° the column wheel mounted in a watch- chronograph. The advance of the column wheel lifting a hammer to release the chronograph hearts and also activating the clutch rocker to start the chronograph hand. The seven "snapshots" are taken every 5 °;
• the figure 6b describes the same moment that the figure 6a but shows the whole mechanism.

DETAILED DESCRIPTION OF AN EMBODIMENT

The figure 1 shows a perspective view of a known type of column wheel. The columns are evenly distributed around the rim. Considering a cross section of a column, a symmetrical profile is obtained, substantially in the form of a truncated triangle, or a trapezium, whose large base is parallel to the circumference of the column wheel and turned towards the outside of the column. the teeth of the ratchet. Such a symmetrical arrangement has advantages in terms of design and especially the manufacture of columns.

The figure 3 shows a perspective view of a column wheel 1 according to a particular embodiment of the invention. The figure 4 presents a view from above of the same column wheel. These two figures make it possible to clearly view the ratchet 2 provided with teeth 3 distributed symmetrically around its periphery. The ratchet 2 is pierced at its center so to provide an assembly element for mounting the wheel 1 in a chronograph device. The ratchet 2 is capped with a superstructure constituted by a hub 21, by arms 20 and by columns 10. The six columns 10 are arranged symmetrically on the periphery of the ratchet 2 thus giving the superstructure 10, 20, 21 a symmetry of rotation of order 6. We can also check on the figure 4 that the ratchet 2 has 12 teeth regularly spaced from each other by 30 °. Those skilled in the art will understand that the column wheel of the present example is a two-stroke column wheel. However, the present invention naturally applies equally well to three-stroke column wheels. The arrow R on the figure 4 illustrates the direction of rotation of the column wheel 1, ie the clockwise direction.

The figure 2 shows a cross-section of a column 10. It is observed that the section of the column generally has a non-isosceles triangle shape truncated in the area of the summit. The three sides of the triangle are the large base 14, located near the edge of the ratchet 2, the leading edge 12, and the trailing edge 13. The leading edge 12 is so designated because it is the first to come into contact with the spout of the lever (s) of the chronograph mechanism during the rotation of the wheel 1. The trailing edge 13 designates the last face to contact the lever before the latter plunges into the inter column space 22 and is free.

Both angles a and 13 adjacent to the large base 14 are rounded. As will be seen below, this feature facilitates the progression of the nozzle of the lever cooperating with the column during operation of the chronograph.

Referring to the figures, it is noted that the truncated or trapezoidal triangle shape of the cross section of a column is asymmetrical, with an angle α less than the angle β, where the angle α represents the angle formed between the large base 14 and the leading edge 12, while the angle β represents the angle formed between the large base 14 and the edge of According to such an arrangement, the leading edge 12 is substantially projected forwardly (in the direction of rotation R) in comparison with a conventional symmetrical arrangement as shown in FIG. figure 1 .

In the illustrated example, the angles α and β are respectively 51.5 degrees and 69.5 degrees. According to various alternative embodiments, the angle α may vary, but it is preferably between 50 and 53 degrees. In the present example, the angle α is about 26% lower than the angle β. According to various embodiments, the distance between the two angles is preferably between 23 and 28%.

The figures 2 , 3 and 4 also allow to clearly visualize the hub 21 and the arms 20 for reinforcing the columns 10. The arms 20 extend between the columns and the hub 21 which is centered on the axis of the wheel. The arms and the hub make it possible to stiffen the construction of the wheel in general, and the columns in particular. This stiffening of the columns allows operation with a particularly high level of precision. In the present example, the hub 21 and the arms 20 have a height less than that of the columns 10. The height of the hub and the arms will preferably be between 10% and 50% of the height of the columns. The column wheel according to the invention is preferably manufactured entirely on a lathe. A manufacture without recovery on a lathe allows to give the piece a remarkable precision.

The figure 5 shows an example of implementation of a column wheel 1 according to the invention in a chronograph control mechanism. In addition to the components of the column wheel already described in relation to the Figures 3 and 4 , the figure 5 shows a jumper 24 whose spout 25 is provided to cooperate with the teeth of the ratchet 2, a hammer lever 40 seconds / minutes mounted to pivot about an axis 42, a clutch rocker 50 with a spout 51 and finally , a blocking lever 30. The figure 6b is a corresponding view showing the main elements of a chronograph. The blocking lever 30 is integral with a shoe 32 and is arranged to cooperate with the wheel. columns to alternately brake and release the chronograph mobile (referenced 5). The hammer lever 40 is pivotally mounted about an axis 42 ( figure 5 and it is provided with a spout 41 capable of cooperating with the columns of the column wheel so as to act on the cores 43 to control and manage the function of return to zero of the chronograph. The figure 6b represents the hammers 40 in a lowered position where it cooperates with the hearts 43. We still see on the figure 6b that the lowered position of the hammer corresponds to a position of the column wheel which allows the spout 41 of the hammer lever 40 to be immersed in the gap existing between two columns 10. This position of the column wheel, identified as 0 degree, serves as a reference. The Figures 6a , and 7 to 12 show the evolution of the position of the wheel, in steps of 5 degrees, to a position of 30 degrees ( figure 12 ).

The snapshot represented at figure 6a corresponds to the 0 ° position of the column wheel. In this position, as already mentioned, the hammer is lowered against the hearts and the hammer beak 41 is positioned freely between two columns 10. We still see on the figure 6a that in position 0 °, the spout 51 of the clutch rocker 50 is in abutment against the outer face of a column 10. The clutch rocker is thus lifted which has the effect of maintaining a return 28 removed from the chronograph wheel 5, and thus to disengage the latter. Note further that the hammer 40 and the blocking lever 30 are shaped to cooperate so that the blocker is held up regardless of the position of the column wheel as the hammer is lowered against the hearts 43.

The snapshot represented at figure 7 corresponds to the 5 ° position of the column wheel. We see that in this position, the hammer 40 and always lowered against the hearts 43 and the blocker 30 is always lifted. However, it is seen that the hammer nose 41 initiates contact with the leading edge of a column A. The spout 41 is substantially tangent to the leading edge. It is therefore understood that the shape of the columns according to the invention allows to distribute as much as possible the forces acting on the nozzle 41. On the other hand, as at the figure 6a , the spout 51 of the clutch rocker 50 bears against the outer face of the column A.

The snapshot represented at figure 8 corresponds to the 10 ° position of the column wheel. It can be seen that in this position, the hammer nose 41 is slightly pushed back by the leading edge of the column A and the hammer has slightly detached from the cores 43. It can also be seen that the clutch rocker nose 51 slides. always against the great base of this same column. Blocker beak 31 is about to initiate contact with column B.

The snapshot represented at figure 9 corresponds to the 15 ° position of the column wheel. We see that in this position, the lifting of the hammer beak 41 is accentuated by the action of the column A. The hammer has now completely released the hearts 43. We also see that the clutch rocker tip 51 arrives near the rear area of the large base 14 of the column A. On the other hand, the hammer 40 is releasing the blocker 31, but simultaneously the jammer nose 31 initiates contact with the outer face of the column B .

The snapshot represented at figure 10 corresponds to the 20 ° position of the column wheel. We see that in this position, the lifting of the hammer beak 41 is almost completed. It is also seen that the clutch rocker nose 51 is about to plunge. On the other hand, the blocker beak 31 is now well against the large base 14 of the column B.

The snapshot represented at figure 11 corresponds to the 25 ° position of the column wheel. It can be seen that in this position, the hammer nose 41 bears against the large base 14 of the column A. The clutch rocker nose 51 has plunged between two columns, but the chronograph mobile 5 is not yet engaged. The blocker nose 31 is still resting against the large base 14 of the column B.

The snapshot represented at figure 12 corresponds to the 30 ° position of the column wheel. It can be seen that in this position, the clutch lever 51 is always lowered between two columns and the gear 28 now meshes with the chronograph mobile which is thus engaged, which corresponds to the start ("start") of the chronograph. The blocker beak 31 remains in abutment against the large base 14 of the column B.

We can see from the above, and especially from Figures 7 to 11 that the stroke made by the hammer lever nose along the leading edge of a column is greater than if the leading edge 12 and the trailing edge 13 were symmetrical. This spreading of the displacement over a greater distance makes it possible to reduce the applied force. These characteristics make it possible to optimize the general mechanical characteristics of the levers: for example, a reduction in friction, wear and energy losses, and a better accuracy of the arrangements of parts and the resulting functions, etc. are obtained. In particular, the execution of the lifting and diving of the levers 30, 40 and 50 by the asymmetric columns with advanced leading edge are performed very precisely with optimized synchronization of the respective movements of the parts during the performance of the functions. of the chronograph. This results in better management of the chronograph functions. This geometry of the columns makes it possible to precisely define the direction of the vectors of forces necessary for the lifting of the levers. A reduction in the forces involved, a better efficiency, a reduction in wear and an increased control of the force to be exerted on the "start / stop" command are thus obtained.

It will be further understood that various modifications and / or improvements obvious to those skilled in the art can be made to the embodiment which is the subject of the present description without departing from the scope of the present invention defined by the appended claims. In particular, the invention and its various variants have just been described in connection with a particular example with six columns. Nevertheless, it is It is obvious to one skilled in the art that the invention may be extended to an embodiment with a different number of columns, especially with eight columns.

Claims (11)

Column wheel (1) for a chronograph comprising: - a ratchet (2) provided with a plurality of teeth (3) whose shape defines a direction of rotation for the column wheel; a coaxial superstructure at the wheel and having a symmetry of rotation of order n> = 3, the peripheral part of the superstructure forming n columns (10) parallel to the axis of the wheel and arranged substantially along the periphery ratchet (2), each column having an outer portion whose cross section has substantially the shape of a truncated triangle with a base substantially parallel to the circumference of the wheel and a front side (12), said leading edge, and a trailing edge (13), said trailing edge, extending from the base towards the inside of the wheel; characterized in that said cross section is asymmetrical, a first angle α between the leading edge (12) and the base (14) being smaller than a second angle β between the base and the trailing edge (13). A column wheel (1) for a chronograph according to claim 1, wherein the base (14) is substantially rounded convex. A column wheel (1) for a chronograph according to claim 1 or 2, wherein the angle α is less than the angle β of at least 10% and preferably at least 20%. A column wheel (1) for a chronograph according to claim 1, 2 or 3 wherein the angle α is between 50 degrees and 53 degrees. Column wheel (1) for chronograph according to any one of the preceding claims, characterized in that the superstructure comprises a hub (21) connected to the columns (10) by arms (20) so as to strengthen them. A column wheel (1) for chronograph according to claim 5, wherein the arms (20) and the hub (21) have a height of between 10% and 50% of the height of the columns. Chromograph control mechanism comprising a column wheel (1) according to any one of claims 1 to 6, and at least one pivoting lever (30, 40, 50) whose beak is capable of cooperating with the columns (10) of the column wheel. The chronograph control mechanism of claim 7, wherein a lever is a clutch rocker (50). The chronograph control mechanism according to claim 7 or 8, wherein a lever is a hammer (40). Chronograph control mechanism according to one of claims 7, 8 or 9, wherein a lever is a blocker (30). Chronograph watch comprising a chronograph control mechanism according to one of claims 7 to 10.

Images