EP2977827A1 - Clock barrel with improved force transmission - Google Patents

Abstract

Barrel (1) comprising a spring (2) cooperating, internally with a bung (4), externally with a track (6) of a drum (7) by a sliding elastic flange (8) -. Said track (6) and flange (8) are non-circular in shape, nested in the free state of said flange (8), and arranged to cooperate an outgrowth (12) of said flange (8) in abutment with a threshold (11) of said track (6) when the torque applied to said flange (8) is less than a torque limit value, and to allow radial shrinkage of said protrusion (12) when said torque is greater than said limit value, to allow the passage of said protrusion (12) crossing said threshold (11) and allow an angular stroke of said flange (8) under the effect of said torque until the next meeting between a said threshold (11) and a said outgrowth (12).

Description

Field of the invention

The invention relates to a watch cylinder, comprising at least one spring cooperating at its inner end with a bung pivoting about a pivot axis, and at its outer end with an inner track of a drum barrel by a flange. slippery elastic.

The invention also relates to a watch movement comprising such a barrel, whose bung is arranged to cooperate with manual winding means.

The invention relates to a timepiece comprising such a movement, and / or at least one mechanism comprising such a cylinder.

The invention relates to the field of time barrels for energy storage comprising a spring.

Background of the invention

The invention relates to the transmission of energy by a mainspring to a barrel drum via an element traditionally called a flange. In general, for manual winding movements, the barrel springs are connected to the drum via a fixed flange. For automatic movements, the transfer of force is via a slidable flange which allows to temporarily disconnect the end of the spring of the drum above a limit declutching torque.

The fixed flange makes it possible to maximize the properties of the spring, in particular the number of turns, but has the disadvantage of generating an overtorque during the maximum arming: the user does not feel that the spring is totally reassembled only when the torque becomes significantly most important. This overtorque can be the cause of problems of fatigue (rupture) but also of chronometric problems.

The slippery flange is essential for automatic movements, however it is difficult for the user who manually goes back his movement to know, in the absence of indication of power reserve, when the barrel is fully reassembled. The presence of a sliding flange generates a variation of the torque when the barrel is armed at the maximum between the upper slip moment (MGM) and the lower slip moment (MGI). Moreover, this system does not allow to control the torque from which the clutch is made. Finally, these components, and in particular the barrel drum, are often subject to wear during aging tests.

Summary of the invention

The invention proposes a new force transmission system between the flange and the barrel drum. It consists of a specific form of the barrel drum (non-cylindrical shape) and a so-called flexible flange, whose shape is adapted to that of the mainspring. Indeed, this flange must be able to transmit the force of the mainspring to the drum, and, according to the invention, has the possibility of deforming so that, when a given torque is reached, the flange can disengage from the drum and thus disarm the barrel spring slightly without rotating the drum.

For this purpose, the invention relates to a watch cylinder, comprising at least one spring cooperating at its inner end with a bung pivoting about a pivot axis, and at its outer end with an inner track of a drum of barrel by a slidable elastic strap, characterized in that said inner track and said sliding elastic flange are each of non-circular shape, and nested one inside the other in the free state of said slidable elastic flange, and are arranged in whereby at least one radially outward protruding outgrowth of said slidable elastic flange cooperates abutting with at least one radially inward projecting threshold of said inner race when the torque applied to said slidable elastic flange is less than a limit value of torque, and further characterized in that at least one said protrusion of said elastic flange slips nte is subjected to radial shrinkage when the torque applied to said sliding elastic flange is greater than said torque limit value, to allow the passage of said protrusion crossing said threshold and allow an angular stroke of said flange under the effect of said torque until the next meeting between a said threshold and a said outgrowth.

The invention also relates to a watch movement comprising such a barrel, whose bung is arranged to cooperate with manual winding means.

The invention relates to a timepiece comprising such a movement, and / or at least one mechanism comprising such a cylinder.

Brief description of the drawings

• la figure 1 représente, de façon schématisée et en plan, un barillet selon l'invention, avec un ressort de barillet porteur d'une bride de forme porteuse d'une pluralité d'excroissances, montée dans un tambour de barillet comportant une succession de logements séparés par des seuils; dans cette configuration, le ressort est complètement armé ;
• la figure 2 représente, de façon schématisée et en perspective, le tambour de la figure 1,
• la figure 3 représente, de façon schématisée et en perspective, le ressort de la figure 1 équipé de sa bride de forme laquelle comporte une alternance d'excroissances et de surfaces de jonction en creux;
• la figure 4 représente, de façon schématisée et en perspective, un ressort selon une variante de la figure 3 avec davantage d'excroissances, convenant aussi au tambour de la figure 2;
• la figure 5 représente, de façon schématisée et en perspective, un ressort selon une variante de la figure 3 avec une alternance d'excroissances et de surfaces de jonction planes, convenant aussi au tambour de la figure 2;
• la figure 6 représente, de façon similaire à la figure 1, un barillet selon l'invention, avec une bride comportant une seule excroissance et un tambour de barillet comportant un logement unique;
• la figure 7 représente une configuration inversée de la figure 6 ;
• la figure 8 représente, sous forme d'un schéma-blocs, une pièce d'horlogerie comportant un mouvement comportant lui-même un tel barillet manoeuvré par un mécanisme de remontage manuel actionnée par une couronne.

Other features and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings, in which:

• the figure 1 represents schematically and in plan, a barrel according to the invention, with a barrel spring carrying a flange of form carrying a plurality of excrescences, mounted in a barrel drum comprising a succession of housings separated by thresholds; in this configuration, the spring is fully armed;
• the figure 2 represents, schematically and in perspective, the drum of the figure 1 ,
• the figure 3 represents, schematically and in perspective, the spring of the figure 1 equipped with its shaped flange which comprises an alternation of excrescences and recessed junction surfaces;
• the figure 4 represents schematically and in perspective, a spring according to a variant of the figure 3 with more excrescences, also suitable for the drum of the figure 2 ;
• the figure 5 represents schematically and in perspective, a spring according to a variant of the figure 3 with an alternation of growths and planar joining surfaces, also suitable for the drum of the figure 2 ;
• the figure 6 represents, similarly to the figure 1 , a barrel according to the invention, with a flange having a single protrusion and a barrel drum having a single housing;
• the figure 7 represents an inverted configuration of the figure 6 ;
• the figure 8 represents, in the form of a block diagram, a timepiece comprising a movement comprising itself such a cylinder operated by a manual winding mechanism actuated by a crown.

Detailed Description of the Preferred Embodiments

• à son extrémité intérieure 3 avec une bonde 4 pivotant autour d'un axe de pivotement D,
• et à son extrémité extérieure 5 avec une piste intérieure 6 d'un tambour de barillet 7 par une bride élastique glissante 8.

The invention relates to a watch cylinder 1, comprising at least one co-operating spring 2:

• at its inner end 3 with a bung 4 pivoting about a pivot axis D,
• and at its outer end 5 with an inner race 6 of a barrel drum 7 by a slidable elastic strap 8.

According to the invention, the inner track 6 and the sliding elastic flange 8 are each of non-circular shape, and they are nested one inside the other in the free state of the slidable elastic flange 8.

The slidable elastic flange 8 comprises at least one protrusion 12 protruding radially outwards.

The inner track 6 has at least one threshold 11 protruding radially inwards towards the pivot axis D.

The inner track 6 and the elastic sliding flange 8 are arranged in such a way that at least one such protrusion 12 cooperates in abutment with at least one such threshold 11, when the torque applied to the slidable elastic flange 8 is less than a given value. torque limit.

And at least one such protrusion 12 is subjected to radial shrinkage, due to the elasticity of the slidable elastic strap 8, when the torque applied to the slidable elastic strap 8 is greater than the limit value of torque, to allow the passage the protrusion 12 crossing the threshold 11, and allow an angular stroke of the flange 8 under the effect of torque until the next meeting between a threshold 11 and an outgrowth 12.

In a preferred embodiment, the slidable elastic flange 8 forms a closed contour.

During the winding, the spring 2 winds progressively around the bung 4 until reaching the maximum armature, and the cooperation between such an outgrowth 12 of the slidable elastic flange 8 with such a threshold 11 of the inner track 6 of said barrel drum 7 forces the slidable elastic flange 8 to deform under the action of the applied torque, to effect a clutch under the action of which the slidable elastic flange 8 and the spring 2 advance a notch.

The relative shapes of the inner race 6 of the barrel drum 7 and the protrusion 12 of the slidable elastic flange 8 are arranged so that the clutch corresponds to a predetermined maximum torque.

Preferably, the clutch is obtained only by an elastic deformation of a portion of the sliding elastic flange 8 greater than 50% of its periphery.

The figure 1 shows the spring 2 fully armed, which means that if the winding continues (manual or automatic), the shape flange 8 will deform to disengage the barrel drum 7.

A cylinder spring 2 of standard shape can either be connected to a flange 8 of independent form by a bonding process, brazing or welding, or preferably form with this flange 8 of a single piece, preferably in the same material.

When the barrel is completely disarmed, the turns are wound directly on the form flange 8.

During the winding, the mainspring 2 winds progressively around the bung 4 until it reaches maximum arming. The specific shape of the drum then forces the form flange 8 to deform so that the clutch takes place. The relative shapes of the drum 7 and the shape flange 8 are optimized so that the clutch torque corresponds to the desired maximum torque, which is determined according to the properties of the mainspring and the coefficient of friction.

When a disengagement is made, that is to say when the shape flange and the barrel spring have advanced a notch, the available torque drum barrel is lower (MGI lower slip moment).

In a particular embodiment, as visible on the Figures 1 and 2 , the inner track 6 has a plurality of peripheral housings 9 each having a bottom 10 located at the greatest distance DMAX of the pivot axis D. These housings 9 are each separated from its neighbor by such a threshold 11 located at the most small distance DMIN from the pivot axis D.

The sliding flange 8 is preferably and preferably integral with the spring 2 with which it then forms a one-piece assembly.

This sliding flange 8 comprises, in the non-limiting embodiments of Figures 1 to 5 , a plurality of such protrusions 12, each of which, in the free state, is of maximum radius RMAX with respect to the pivot axis D. These protrusions 12 are each separated from its neighbor by a junction surface 13 comprising a zone of minimum radius RMIN with respect to the pivot axis D, the maximum radius RMAX in the free state being greater than the minimum distance DMIN and less than the maximum distance DMAX.

The joining surfaces 13 can be left-handed, concave or convex, or flat as on the figure 5 .

The radial shrinkage of the protuberances 12, thanks to the elasticity of the sliding flange 8, and under the action of the applied torque, makes it possible to reduce their radius of passage relative to the pivot axis D to a value less than or equal to at the minimum distance DMIN to pass such a threshold 11.

The invention is also usable with a barrel whose inner track 6 has only one housing 9, as visible on the figure 6 . The figure 7 also illustrates a configuration with a single housing 9, but operating in an inverted manner, the sliding flange 8 still being in friction against a wall of the inner track 6, except when its protrusion 12 cooperates with the housing 9: the sensation for the user who manually raises his watch is similar, albeit reversed, and he feels just as distinctly the passage of a notch. These two Figures 6 and 7 also illustrate a flange 8 with a single protrusion 12.

It is still possible to use a barrel with several housings 9, as visible on the figure 2 with a sliding flange 8 which has a single protuberance.

In the maximum arming position of the spring 2, each passage of a threshold 11 by a protrusion 12 reduces the available torque at the drum 7 from a higher slip value MGS to a lower slip moment value MGI, which is less than the upper slip value MGS.

In some variants, such as on Figures 1 and 2 , the inner race 6 comprises a plurality of peripheral housings 9 of cycloidal shape. The figure 2 shows a flange 8 with five cycloids, but in another version it is possible to have more or less depending on the desired sizing, for example ten on the figure 4 .

In some variants, such as on Figures 1 and 2 , the inner race 6 and the sliding elastic strap 8 are of identical shape and of homothetic dimensions.

In some embodiments, the inner track 6 and the slidable elastic flange 8 are of different shapes, depending on the desired sizing. We can example combine the springs 2 of Figures 4 and 5 with the drum 7 of the figure 2 .

In some embodiments, the inner track 6 has a first number of thresholds 11, the slidable elastic flange 8 has a second number of excrescences 12, and the second number is greater than or equal to the first number. In other variants, the inner track 6 has a first number of thresholds 11, the sliding elastic flange 8 has a second number of growths 12, and the second number is smaller than the first number.

In a particular variant, the spring 2 is fixed at several points of the slidable elastic flange 8.

The invention is applicable to any type of barrel: movement drive barrel, or ringer barrel, or other.

The invention also relates to a clockwork movement 30 comprising such a barrel 1, whose plug 4 is arranged to cooperate with manual winding means 20, for example by means of a ratchet or the like.

The invention relates to a timepiece 40 comprising such a movement 30, and / or at least one mechanism comprising such a barrel 1, such as a striking mechanism, or a waking mechanism, or the like. Preferably, this timepiece is a watch.

• le système permet de maîtriser directement le couple de débrayage du ressort de barillet 2 avec le tambour (MGS) via le dimensionnement de la bride de forme 8 ;
• le système peut être intégré à un mécanisme à remontage manuel 20, commandé par une couronne 21, ou une targette, ou similaire, et limiter ainsi le surcouple présent généralement à l'armage maximal quand on utilise une bride fixe. Ceci permet de limiter l'augmentation des contraintes, qui constituent une cause de rupture directe ou par fatigue, et également d'éviter les problèmes chronométriques causés par le surcouple (notamment le rebat) ;
• ce type de géométrie permet d'introduire une sensation de crans pour l'utilisateur lors de la manoeuvre de remontage lorsque l'armage maximum est atteint. ;
• l'invention permet de réaliser la fonction de débrayage au travers de la déformation globale d'un composant élastique : à égalité de couple de débrayage, la contrainte dans la bride est inférieure à celle d'un barillet classique ;
• le ressort peut, encore, être fixé en plusieurs points de la bride afin de mieux répartir la contrainte dans la liaison entre le ressort et la bride ;
• l'invention est utilisable pour tous les mouvements ou mécanismes horlogers et assimilés, notamment les boîtes à musique, qui utilisent un ressort de barillet comme source d'énergie, et en particulier les mouvements à remontage manuel, en remplacement d'une bride fixe.

The invention provides many advantages:

• the system makes it possible to directly control the disengaging torque of the mainspring 2 with the drum (MGS) via the dimensioning of the form flange 8;
• the system can be integrated with a manual winding mechanism 20, controlled by a ring 21, or a bolt, or the like, and thus limit the overtorque usually present at the maximum armature when using a fixed flange. This makes it possible to limit the increase in stresses, which constitute a cause of direct or fatigue failure, and also to avoid the chronometric problems caused by the over-torque (especially the rebate);
• this type of geometry makes it possible to introduce a sensation of notches for the user during the winding maneuver when maximum arming is reached. ;
• the invention makes it possible to perform the disengaging function through the overall deformation of an elastic component: at equal release torque, the stress in the flange is smaller than that of a conventional barrel;
• the spring can also be fixed at several points of the flange to better distribute the stress in the connection between the spring and the flange;
• the invention is usable for all movements or mechanisms and similar watchmaking, including music boxes, which use a mainspring as a power source, and in particular manual winding movements, replacing a fixed flange.

Claims (16)

Timepiece (1) having at least one spring (2) cooperating at its inner end (3) with a bung (4) pivoting about a pivot axis (D), and at its outer end (5) with an inner race (6) of a barrel drum (7) by a slidable elastic flange (8), characterized in that said inner track (6) and said slidable elastic flange (8) are each of non-circular shape, and nested one inside the other in the free state of said slidable elastic flange (8), and are arranged such that at least one protrusion (12) projecting radially outwardly that comprises said elastic flange slider (8) cooperates in abutment with at least one radially inwardly projecting threshold (11) provided by said inner track (6) when the torque applied to said slidable elastic flange (8) is less than a torque limit value, and further characterized in that at least one said outgrowth (12) of said slidable elastic flange (8) is subjected to radial necking when the torque applied to said slidable elastic flange (8) is greater than said torque limit value, to allow passage of said outgrowth (12) crossing said threshold (11) and allow an angular stroke of said flange (8) under the effect of said torque until the next meeting between a said threshold (11) and a said protrusion (12). Barrel (1) according to claim 1, characterized in that said slidable elastic flange (8) forms a closed contour. Barrel (1) according to claim 1 or 2, characterized in that during winding, said spring (2) winds progressively around said bung (4) until reaching the maximum armor, and in that the cooperation between a said protuberance (12) of said slidable elastic flange (8) with a said threshold (11) of said inner track (6) of said barrel drum (7) forces said slidable elastic flange (8) to deform under the action of the torque applied to effect a clutch under the action of said slidable elastic flange (8) and said spring (2) advance one notch. Barrel (1) according to claim 3, characterized in that the relative shapes of said inner track (6) of said barrel drum (7) and said protuberance (12) of said slidable elastic flange (8) are arranged so that said disengagement corresponds to a predetermined maximum torque. Barrel (1) according to claim 3 or 4, characterized in that said clutch is obtained only by an elastic deformation of a portion of said slidable elastic flange (8) greater than 50% of its periphery. Barrel (1) according to one of claims 1 to 5, characterized in that said inner track (6) comprises a plurality of peripheral housings (9) each having a bottom (10) located at the greatest distance (DMAX) of said pivot axis (D), and said housings (9) being each separated from its neighbor by a said threshold (11) located at the smallest distance (DMIN) from said pivot axis (D), and in that said sliding flange (8) is integral with said spring (2) with which it forms a one-piece assembly, and has a plurality of said protuberances (12) each in the free state of maximum radius (RMAX) with respect to said pivot axis (D) and each separated from its neighbor by a joining surface (13) having a zone of minimum radius (RMIN) with respect to said pivot axis (D), said maximum radius (RMAX) in the free state being greater than said minimum distance ( DMIN) and less than said maximum distance (DMAX). Barrel (1) according to claim 6, characterized in that said radial narrowing of said protrusions (12) allows the reduction of their radius with respect to said pivot axis (D) to a value less than or equal to said minimum distance (DMIN) for to pass a said threshold (11). Barrel (1) according to one of the preceding claims, characterized in that , in the maximum arming position of said spring (2), each passage of a said threshold (11) by a said protrusion (12) reduces the available torque at said drum (7) a higher slip value (MGS) than a lower slip value (MGI) which is lower than said upper slip value (MGS). Barrel (1) according to one of the preceding claims, characterized in that said inner track (6) comprises a plurality of peripheral housings (9) of cycloidal shape. Barrel (1) according to one of the preceding claims, characterized in that said inner track (6) and said slidable elastic flange (8) are of identical shape and homothetic dimensions. Barrel (1) according to one of the preceding claims, characterized in that said inner track (6) and said sliding elastic flange (8) are of different shapes. Barrel (1) according to one of the preceding claims, characterized in that said spring (2) is fixed at several points of said slidable elastic flange (8). Barrel (1) according to one of the preceding claims, characterized in that said inner track (6) comprises a first number of said thresholds (11), in that said slidable elastic flange (8) comprises a second number of said excrescences (12), and said second number is greater than or equal to said first number. Barrel (1) according to one of claims 1 to 12, characterized in that said inner race (6) comprises a first number of said thresholds (11), in that said sliding elastic strap (8) comprises a second number of said excrescences (12), and said second number is less than said first number. Clockwork movement (30) comprising a barrel (1) according to one of the preceding claims, wherein said bung (4) is arranged to cooperate with manual winding means (20). Timepiece (40) comprising a movement (30) according to the preceding claim. or / and at least one mechanism comprising a said barrel (1) according to one of claims 1 to 14.

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