EP2546706B1 - Clockwork including a module provided with a mobile meshing with another mobile pivoting in a base on which the module is mounted - Google Patents

Description

Technical area

The present invention relates to a clockwork comprising a module provided with a first mobile meshing with a second mobile pivoting in a base on which is mounted the module. In particular, the invention relates to a clockwork comprising an exhaust-holder forming a module in which the exhaust is arranged, namely the balance spring, the anchor and the escapement mobile. This mobile exhaust is formed of an exhaust plate and an exhaust pinion which, in the finished movement, meshes with a wheel of the train mounted on the plate on which is fixed the exhaust door.

Technological background

When there is no particular problem for fixing the module on the basis of the watch movement, in particular on the plate, by a vertical translation allowing to mesh a first mobile of the module with a second mobile pivoted in this base, the The module is generally positioned by two feet (or pins) machined or arranged in the base, which penetrate into two respective holes machined in a plate or bridge of the module. Once positioned, the module is fixed by at least one screw to the base. Given the manufacturing tolerances for the feet, the holes and the bearings of the first and second mobiles in various parts of the blank, we obtain an approximate positioning of the module and a significant variation in the distance between these first and second mobile. This poses a real problem for the movement of the watch movement because a non-optimal meshing of the first and second mobiles decreases the yield and causes a variation thereof. The amplitude of the balance is generally decreased and the accuracy of the step is affected. In this respect, a precise and well-defined meshing between the cog and the exit of an exhaust door is particularly important.

In general, positioning of the module by a simple vertical translation is not possible. A solution to this particular problem is given in particular in the documents CH-578 203 / US 3802183 and CH-581 342 / US 3945197 . These documents propose a mounting of an exhaust door by a vertical translation to arrange it in a guide hole of the exhaust holder on a foot of the plate (pin or cylinder threaded inside for a fixing screw) around which he can turn. Then, the exhaust carrier is rotated until two respective parts of the exhaust carrier and the rest of the movement abut against each other. In the first document, it is expected that a column (pin) of the exhaust-holder comes to bear against a side wall of a bridge in which the second wheel rotates with which the exhaust pinion must mesh. In the second document, it is expected that a zone of an exhaust-door plate comes to bear against a deck mounted on the plate. In both cases, the problem of the various manufacturing tolerances which vary the spacing of the exhaust pinion and the second wheel remains intact.

To the Figures 1 to 3 is represented a movement in which is mounted an exhaust holder 2 on a plate 4 according to the technique mentioned above. The escapement mobile 6 is pivotally mounted between a lower plate 8 and an upper deck 10 of the exhaust-door, just like the rocker 12. At the Figure 1 , the exhaust carrier is mounted on a foot or, as shown, on an internally threaded cylinder 16 around which it can rotate to be brought by a horizontal rotation in a final position shown in FIGS. Figures 2 and 3 . In this position final, the pinion 18 of the escapement mobile meshes with a wheel 14 of the gear mounted on the plate. To maintain the exhaust door in its final position, two fixing screws are provided, the first being screwed into the cylinder 16 and the second being screwed into a threaded hole 20 of the plate through a frustoconical hole 22 provided in the upper deck 10. The mounting tolerances of the escapement wheel and the wheel 14 respectively in the exhaust holder and on the plate do not allow to obtain a precise and predetermined spacing. In addition, mounting the exhaust door on the plate has a significant tolerance that greatly increases the problem. Thus, the penetration of the gear pinion 18 into the toothing of the wheel 14 is not precisely determined and has an uncontrolled variable character which negatively influences the operation of the exhaust.

In general, when a module, defining a distinct unit with at least one first pivoting mobile in this module, is arranged on a watch movement basis and this first mobile must mesh with a second mobile pivoting on the base, there is has a problem that the distance between the first and second mobiles varies around the optimum distance; which affects the smooth running of the watch movement. Indeed, the meshing between the first and second mobile is pejorated by many manufacturing tolerances; this particularly with the planned modular construction. Thus it is difficult to obtain a predetermined distance.

Summary of the invention

It is an object of this invention to overcome the aforementioned randomly variable spacing problem in a modular construction.

For this purpose, the subject of the present invention is a watch movement comprising a module, provided with a first mobile unit meshing with a second pivoting mobile in a base on which this module is mounted, and means for positioning the module on the based. The positioning means are formed by an eccentric whose profile / periphery at least defines for the most part an Archimedean spiral or an optimized Archimedean spiral, this eccentric being arranged in such a way that it makes it possible to adjust the spacing between the first and second movable when rotated about the geometric center of said Archimedes spiral or said optimized Archimedean spiral. Preferably, the eccentric is calibrated.

The invention also relates to a method of adjusting the distance between a first watch mobile, pivotally mounted in a module that is rotatable about a geometric axis relative to a base on which it is mounted, and a second mobile watchmaker pivoting on said base. The steps of this process are given in appended claim 6.

In a particular embodiment of the invention, the module is an exhaust door, the first mobile being the exhaust pinion and the second mobile being a wheel of the train mounted on a plate defining the base.

Other particular features of the invention will be described below in the detailed description of the invention.

Brief description of the drawings

• La Figure 1 est une vue de dessus d'un mouvement de l'art antérieur sur lequel est monté un porte-échappement, ce dernier étant dans une position initiale de son montage dans le mouvement ;
• La Figure 2 est une vue de dessus du mouvement de la Figure 1 avec le porte-échappement dans une position finale ;
• La Figure 3 est une vue en coupe selon la ligne III-III de la Figure 2 ;
• La Figure 4 est une vue partielle et schématique de dessus d'un mode de réalisation d'un mouvement horloger dans lequel est monté un porte-échappement selon l'invention, ce dernier étant dans une position initiale ;
• La Figure 5 est une vue similaire à celle de la Figure 4 avec le porte-échappement dans une position intermédiaire de son montage ; et
• La Figure 6 est une vue similaire à celle de la Figure 4 avec le porte-échappement dans une position finale de son montage.

The invention will be described hereinafter with the aid of annexed drawings, given by way of non-limiting examples, in which:

• The Figure 1 is a top view of a movement of the prior art on which is mounted an exhaust door, the latter being in an initial position of its assembly in the movement;
• The Figure 2 is a top view of the movement of the Figure 1 with the exhaust door in a final position;
• The Figure 3 is a sectional view along line III-III of the Figure 2 ;
• The Figure 4 is a partial schematic top view of an embodiment of a watch movement in which is mounted an exhaust door according to the invention, the latter being in an initial position;
• The Figure 5 is a view similar to that of the Figure 4 with the exhaust door in an intermediate position of its assembly; and
• The Figure 6 is a view similar to that of the Figure 4 with the exhaust door in a final position of its assembly.

Detailed description of the invention

With the help of Figures 4 to 6 , schematically below will be described a clockwork movement of the type described above using the Figures 1 to 3 but incorporating the present invention. The watch movement 30 is partially represented. On the one hand, there is shown the seconds wheel 32 which is pivotally mounted between the plate 4 and a bridge 34 and, on the other hand, an exhaust door 36 carrying an escape wheel, of which only the exhaust pinion 18 is represented. This is sufficient to describe the present invention.

1. A) Montage du module 36, notamment un porte-échappement, sur la base 4 dans une position initiale (Figure 1) dans laquelle les premier et deuxième mobiles n'engrènent pas, de manière que ce porte-échappement puisse, avant qu'il soit le cas échéant fixé rigidement à cette base, tourner autour d'un axe géométrique 38 et qu'une première surface latérale 48 de ce module, distante de cet axe géométrique, puisse être en appui contre l'excentrique 40 sur une certaine distance angulaire lorsque cet excentrique est tourné sur lui-même, notamment à l'aide d'un tournevis inséré dans la fente 44 de cet excentrique monté à friction sur un axe 46 centré sur le centre de la spirale d'Archimède ou de la spirale d'Archimède optimisée ;
2. B) Rotation du module autour de l'axe géométrique 38 jusqu'à ce que la denture 50 du premier mobile 18 pénètre la denture 52 du deuxième mobile 14 et vienne en butée contre ce deuxième mobile (Figure 5) ;
3. C) Positionnement angulaire de l'excentrique 40 de manière que celui-ci soit en appui contre la surface latérale 48 dudit module avec les premier et deuxième mobiles dans la position relative résultant de l'étape B) ci-dessus (Figure 5) ;
4. D) Suite à l'étape C), rotation de l'excentrique sur une distance angulaire correspondant sensiblement à une translation déterminée du premier mobile relativement au deuxième mobile et maintien de la surface latérale 48 en appui contre l'excentrique, de manière à augmenter l'entraxe L en retirant partiellement la denture 50 du premier mobile de la denture 52 du second mobile sensiblement sur une distance déterminée (Figure 6).

According to a first embodiment of the method of adjusting the center distance L between a first watchmaker mobile 18, pivotally mounted in a module 36 which is capable of being rotated about a geometric axis 38 relative to a base 4 on which it is mounted, and a second mobile watch 32 pivoting on the base, it is provided according to the invention to arrange on the base an eccentric 40 whose periphery 42 defines at least on its major part an Archimedes spiral or a Archimedean spiral optimized. This process comprises the following steps:

1. A) Mounting of the module 36, in particular an exhaust holder, on the base 4 in an initial position ( Figure 1 ) in which the first and second movers do not mesh, so that the exhaust holder can, before it is optionally fixed rigidly to this base, rotate about a geometric axis 38 and a first lateral surface 48 of this module, remote from this geometric axis, can be in abutment against the eccentric 40 over a certain angular distance when the eccentric is turned on itself, in particular with the aid of a screwdriver inserted in the slot 44 of this eccentric frictionally mounted on an axis 46 centered on the center of the Archimedes spiral or the optimized Archimedean spiral;
2. B) Rotating the module around the geometric axis 38 until the toothing 50 of the first mobile 18 enters the toothing 52 of the second mobile 14 and abuts against this second mobile ( Figure 5 );
3. C) Angular positioning of the eccentric 40 so that it rests against the lateral surface 48 of said module with the first and second mobiles in the relative position resulting from step B) above ( Figure 5 );
4. D) Following step C), rotating the eccentric over an angular distance substantially corresponding to a determined translation of the first mobile relative to the second mobile and maintaining the lateral surface 48 against the eccentric, so as to increase the center distance L partially removing the toothing 50 of the first mobile of the toothing 52 of the second mobile substantially over a predetermined distance ( Figure 6 ).

In the embodiment shown in Figures 4 to 6 , the module 36 is an exhaust door, the first mobile 18 is the exhaust pinion and the second mobile 14 is a wheel 32 of the train mounted on a plate 4 defining said base. In a particular variant, the wheel 32 is the seconds wheel.

According to the invention, the lateral surface 42 of the eccentric 40 forming its periphery substantially defines an Archimedean spiral in a plane perpendicular to its axis of rotation. The Archimedean spiral is the polar equation curve R = P · θ where R is the radius in the center and θ the angle traveled from the origin, that is to say the center of the spiral. The parameter P can be chosen according to the particular configuration and the value of the expected withdrawal for optimize the meshing of the two mobiles. It can have a positive or negative mathematical sign. Note that the eccentric 40 corresponds to a negative sign. The spiral thus has a pitch of P · 2π and has a remarkable characteristic, namely that its distance to the center always increases by the same value for a given increase of the angle θ whatever the initial value θ0. This has the consequence that a rotation of the eccentric of a given angle corresponds to a determined increase of the radius R whatever the initial position of the eccentric. The invention takes advantage of this particular feature. When it is mentioned here that the lateral surface of the eccentric defines an Archimedean spiral, it is understood that it corresponds to a turn of such a spiral, for example the tenth or the twentieth. In an improved variant, the Archimedes spiral is optimized because the center of this spiral is distinct from that of the two mobiles and the support surface of the module against the eccentric is not always perpendicular to the direction of rotation (direction tangential) of this module. The Archimedes spiral is thus optimized by calculation as a function in particular of the positions of the two mobiles, the position of the eccentric and the bearing surface of the module against this eccentric in order to have the linear characteristic provided between angle of rotation of the eccentric and the variation of the distance between the two mobiles.

The method according to the invention therefore proposes to insert the teeth of the two mobiles in question until the mobiles are in abutment against each other. This defines a particular position that is not influenced by manufacturing tolerances. In this particular position, the center distance is essentially defined by the dimensions of the two mobiles that mesh. It will be noted that the lateral play of the mobiles in their respective bearings has the consequence that the two mobiles are not exactly in their free position. This phenomenon can be taken into account when determining the angular distance involved in step D) of the method according to the invention described above.

The angle of rotation of the eccentric 40 corresponds to a determined translation of said first mobile relative to said second mobile, and this that is the initial position of this eccentric when the two mobile are in abutment. Thus, this determined translation used to optimize meshing is freed from the various manufacturing tolerances with the exception of manufacturing tolerance of the eccentric. This follows from the specific profile provided for the periphery of the eccentric. In a preferred variant, the eccentric is calibrated so that the angle of rotation necessary to obtain the aforementioned determined translation corresponds to a predetermined angle.

To maintain correctly the module, in particular its lateral surface in contact with the eccentric, bearing against this eccentric during the controlled withdrawal of the toothing 50 of the first mobile of the toothing 52 of the second mobile, a spring 56 is provided in a variant of the process of the invention. This spring is preferably mounted after bringing the exhaust holder on the plate and bringing it to a position where the two wheels are in contact. Alternatively, to gently bring the two mobile abutment, we can use the eccentric turning in the direction that decreases the distance between the two mobiles. In another variant, once the two movers abut against each other, the eccentric 40 is angularly positioned so that it is in abutment against the lateral surface 48 of the module 36. In this configuration it has an initial position for example as represented in Figure 5 . Then, the practitioner or an automaton turns the eccentric in the direction that distances the first mobile from the second mobile

The axis of the eccentric will preferably be arranged as a function of the dispersion of the manufacturing tolerances so that the point or zone of contact of this eccentric with the lateral surface 48 of the module 36 is located, if possible, substantially in a predefined zone of the turn defined by the periphery of the eccentric. To do this, we will take into account the maximum tolerance at the lateral bearing surface 48 in the intermediate position where the two mobiles support one against the other relative to the eccentric mounted on the plate 4 and also the direction in which the eccentric is rotated to perform the controlled and predetermined withdrawal. As an example in the case of an exhaust door, the expected withdrawal is 0.05 mm to ensure proper operation of the movement. If the maximum tolerance for positioning the axis of the eccentric relative to the contact surface of the exhaust carrier is, for example, +/- 0.075 mm, the pitch of the selected hairspring must be at least 0.2 mm at the withdrawal of 0.05 mm and the maximum variation of 0.15 mm in the relative positioning of the eccentric with the module. Since the angular distance for the withdrawal is always in the same direction, the theoretical position of the axis of the eccentric is provided so that in the theoretical position of contact with the module in its aforementioned intermediate position is at a corresponding angular distance. to an increase of 0.075 mm since the recess 58 around the eccentric in the direction of rotation away from the first mobile of the second mobile. Thus one ensures to be able to perform the rotation of the eccentric to perform the translation of 0.05 mm for the purpose of removal in all cases. In the example given, the expected shrinkage advantageously corresponds to a 90 ° angle, which a practitioner can perform approximately easily by a simple observation of the initial position of the slot 44 on the eccentric in the intermediate position and a visual identification of the final position in which the eccentric must be brought; namely here at the perpendicular of the initial position. Note that, because of the recess 58, we will preferably choose a spiral pitch a little higher than the limit case.

In a second embodiment of the method of the invention (not shown), the eccentric is mounted in the module 36 and is therefore integral therewith. In this case, the lateral surface against which this eccentric is supported is that of a portion secured to the base 4. The method of adjusting the distance between the two mobiles remains similar to that of the first embodiment described above. . This is a technical reversal that the person skilled in the art will easily conceive.

In a preferred variant where it is intended to rigidly fix the module in its final position by at least one fixing screw, the upper bridge has an oblong hole 62 in front of which is located a threaded hole 64 in the plate 4. The holder Exhaust is thus fixed in the final position by means of a flat head screw 76 through the oblong hole. The tapped hole can also be provided in a pin that fits partially into the oblong hole. At the axis of rotation 38 of the exhaust carrier is also provided a tapped hole 66 coaxial with this axis of rotation for a second fastening screw 78.

It will be noted that the method of adjusting the distance according to the invention can also be achieved by an eccentric arranged temporarily on the base or on the module, in particular by means of a tool comprising the eccentric of the invention. The tool and the base or module then comprise complementary means for positioning the tool at a given location and to rotate the tool accurately to achieve the intended adjustment, especially around a geometric axis passing through the center Archimedean spiral or Archimedean spiral optimized.

The invention also relates to the horological movement 30 arranged to implement the method of adjusting the meshing of two mobiles described above. This watch movement comprises a module 36 provided with a first mobile 18 meshing with a second mobile 32 pivoting on a base 4 on which is mounted the module. This module, before it is optionally fixed rigidly to the base, is mounted on this base so that it can rotate horizontally about a geometric axis 38. In the embodiment shown in FIGS. Figures 4 to 6 , a foot or a pin 66 of the base is arranged in a hole of the module 36. According to the invention, the movement comprises positioning means formed by an eccentric 40 whose periphery 42 at least defines for the most part a spiral of 'Archimedes. Preferably, the eccentric is calibrated. The choice of the Archimedean spiral has been explained previously.

A lateral surface 48 of the module 36, remote from the geometric axis 38, is capable of being pressed against the eccentric over a certain angular distance when it is turned on itself. In particular, this lateral surface can be pressed against the eccentric at least when the latter is turned between an intermediate position, in which the two mobiles 18 and 32 abut against each other with their respective teeth that penetrate each other. , and a final position in which these two mobiles are spaced from each other by a given distance to release them and increase the efficiency of the meshing of the two mobiles. The lateral surface 48 is situated in a first zone opposite, relative to a geometric plane 70 defined by the parallel axes of rotation 72 and 74 of the first and second mobiles, to a second zone in which the geometric axis 38 is located. L between these two axes of rotation defines the center distance which is adjusted according to the invention by turning the eccentric substantially over a given angular distance, corresponding to a determined translation of the first mobile relative to the second mobile, from a particular position in which the toothing of the first module penetrates to the maximum the toothing of the second mobile. This particular position has the advantage of being determined only by the dimensions of both mobiles and to overcome manufacturing tolerances. With the eccentric according to the invention, it is possible to make a determined withdrawal to optimize the relative position of the teeth of the two mobiles.

As already mentioned, the present invention is particularly useful when the module is an exhaust door, the first mobile being the exhaust pinion and the second mobile being a wheel of the gear mounted on a plate defining said base. In general it is the last wheel of the wheel, especially the seconds wheel.

Claims (10)

1. Timepiece movement (30) including a module (36), fitted with a first wheel set (18) meshing with a second wheel set (32) pivoting on a base (4), on which said module is mounted, and means for positioning the module on said base, characterized in that said first and second wheel sets are separated by an adjustable distance of centres (L), and in that said positioning means is formed by a cam (40), at least most of the periphery (42) of which defines an Archimedes' spiral or an optimized Archimedes' spiral, said cam being arranged to allow said distance of centres (L) between the first and second wheel sets to be adjusted when the cam is rotated about the centre (46) of said Archimedes' spiral or of said optimized Archimedes' spiral, the latter being optimised such that said distance of centres varies linearly as a function of the angle of rotation of the cam.
2. Timepiece movement according to claim 1, characterized in that said cam is substantially calibrated.
3. Timepiece movement according to claim 1 or 2, characterized in that, prior, if necessary, to being rigidly fixed to said base, said module is capable of rotating about a geometric axis (38) and in that a lateral surface (48) of the module, remote from said geometric axis, is capable of remaining in abutment against said cam, fixed to said base, over a certain angular distance when said cam is rotated about the centre (46) of said Archimedes' spiral.
4. Timepiece movement according to claim 3, characterized in that said lateral surface (48) is located in a first area opposite, relative to a geometric plane (70) defined by the parallel axes of rotation (72, 74) of the first and second wheel sets, to a second area in which said geometric axis is located.
5. Timepiece movement according to any of the preceding claims, characterized in that said module is a platform escapement, said first wheel set being the escape pinion and said second wheel set being a gear train wheel mounted on a bottom plate forming said base.
6. Method for adjusting the distance of centres (L) between a first timepiece wheel set (18), mounted to pivot inside a module (36), which is capable of undergoing rotation about a geometric axis (38) relative to a base (4) on which said module is mounted, and a second timepiece wheel set (32) pivoting on said base, said method being characterized in that said first and second wheel sets are separated by an adjustable distance of centres (L), in that there is permanently or temporarily arranged on the base or on the module a cam (40), at least most of the periphery (42) of which defines an Archimedes' spiral or an optimized Archimedes' spiral, and in that the method includes the following steps:

   A) Mounting the module on said base, so that, prior, if necessary, to being rigidly fixed to the base, the module can rotate about said geometric axis and so that a lateral surface (48) of said module, or of a part fixed to said base, depending on whether the cam is respectively fixed to the base or the module, can abut against said cam over a certain angular distance when said cam is rotated about the centre of said Archimedes' spiral or of said optimized Archimedes' spiral; the latter being optimised such that said distance of centres varies linearly as a function of the angle of rotation of the cam;

   B) Rotating said module about said geometric axis until the toothing of the first wheel set penetrates the toothing of the second wheel set and abuts against said second wheel set;

   C) Angularly positioning said cam so that the cam abuts against said lateral surface with the first and second wheel sets in the relative position resulting from step B);

   D) After step C), rotating said cam over an angular distance substantially corresponding to a determined translation of said first wheel set relative to said second wheel set, so as to increase said distance of centres substantially by a determined distance by partially withdrawing the toothing of the first wheel set from the toothing of the second wheel set and holding said lateral surface in abutment against said cam.
7. Method according to claim 6, characterized in that said cam is calibrated so that said angular distance corresponds to a predetermined angle.
8. Method according to claim 6 or 7, characterized in that said lateral surface is held in abutment against said cam by a spring (56).
9. Method according to any of claims 6 to 8, characterized in that said module is a platform escapement, said first wheel set being the escape pinion and said second wheel set being a gear train wheel mounted on a bottom plate forming said base.
10. Method according to any of claims 6 to 9, characterized in that, after step D), said module is rigidly secured to said base by at least one fixing screw (76).

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