EP3106927B1 - Power reserve indicator for a timepiece - Google Patents

Description

Field of the invention

The invention relates to a clockwork motor comprising a barrel, pivoting around a shaft, enclosing a spring mounted between said barrel and said shaft, which pivotally bears a ratchet for driving said shaft, said motor comprising a differential, a first input is driven indirectly by said ratchet and a second input of which is said drum, and the output of which is a pivoting output wheel, coaxial with said shaft, arranged to constitute or drive a power reserve indicator, and where said differential comprises balls arranged to drive housings of said output wheel forming a basket, and cooperating with an upper surface of said barrel and with a lower surface, which is arranged on the side of said upper surface of said drum, of a differential board, which board is arranged to pivot on said shaft, coaxial with it, and is connected to said ratchet by a friction means, and which constitutes the adite first entry.

The invention also relates to a timepiece movement comprising at least one such motor.

The invention also relates to a watch, or timepiece, comprising at least one such motor, and / or at least one such movement.

The invention relates to the field of mechanical timepieces, in particular watches, comprising as energy source at least one spring barrel motor.

The invention relates to the complication of displaying the available power reserve.

Invention background

The indication of the power reserve of a mechanical watch, supplied with energy by one or more barrels, is a useful complication for the user.

It is nevertheless not very common, because it often requires a consequent modification of the basic movement, and this complication consumes a lot of space, both in volume and in thickness. It is therefore often reserved for movements housed in fairly spacious boxes, and its generalization is difficult.

The document EP1970778 in the name of MONTRES BREGUET SA describes a power reserve indicator comprising a planetary differential gear, of rather complex execution, of which a first input is connected to the barrel shaft, a second input to the barrel, and an output to an indicator power reserve. The frame of the differential gear is coaxial with the barrel shaft, the second inlet being secured to the barrel cover. The output is a crown with internal teeth, which is kinematically connected to the first input by satellites in engagement with each other, and which are carried by the cover.

The document DE1015747 on behalf of FELSA AG describes a similar differential, with first input is connected to the barrel shaft via a gear train, a second input to the barrel, and a differential output at an output wheel which comprises housings of balls or rollers interposed between the barrel and the last mobile of this train.

Summary of the invention

The invention proposes to provide a power reserve display device which is easy to produce by transforming an existing mechanical movement, inexpensive, and consuming the minimum of space.

To this end, the invention relates to a timepiece motor according to claim 1.

The invention also relates to a timepiece movement comprising at least one such motor.

The invention also relates to a watch, or timepiece, comprising at least one such motor, and / or at least one such movement.

Brief description of the drawings

• la figure 1 représente, de façon schématisée, en coupe passant par son axe de pivotement, un moteur d'horlogerie à barillet ne faisant pas partie de l'invention et qui comporte un mécanisme différentiel coaxial à billes permettant la visualisation de la réserve de marche restante au niveau d'un indicateur commandé par une roue de sortie qui est la roue servant de panier aux billes du différentiel ;
• la figure 2 représente, de façon similaire, un indicateur de réserve de marche sur la base du mécanisme de la figure 1, complété avec des rouages d'armage pour la transmission de mouvement entre un rochet et une planche de différentiel servant de première entrée au différentiel à billes, la deuxième entrée étant quant à elle constituée par le barillet lui-même;
• la figure 3 représente, de façon similaire, une réalisation ne faisant pas partie de l'invention mais proche de l'invention, avec un indicateur de réserve de marche sur la base du mécanisme de la figure 1, complété avec un rouage d'armage planétaire pour la transmission de mouvement entre un rochet et une planche de différentiel servant de première entrée au différentiel à billes, la deuxième entrée étant quant à elle constituée par le barillet lui-même;
• la figure 4 est un schéma-blocs illustrant une montre comportant un mouvement incorporant un indicateur de réserve de marche, un moteur, et un différentiel à billes coaxial selon l'invention ;
• la figure 5 représente, de façon similaire aux figures 1 à 3, mais plus schématique, une réalisation ne faisant pas partie de l'invention mais proche de l'invention, avec un moteur d'horlogerie à barillet comportant un mécanisme différentiel coaxial à billes, dans lequel un rochet forme directement le couvercle du barillet ;
• la figure 6 représente, de façon similaire aux figures 1 à 3, une vue partielle d'une autre variante d'indicateur de réserve de marche, selon l'invention, comportant un sous-ensemble différentiel amovible en un seul bloc ;
• la figure 7 représente, de façon schématisée et en perspective, un tel sous-ensemble différentiel, vu depuis un côté supérieur opposé à un côté inférieur où sont saillantes les billes ;
• la figure 8 représente, de façon schématisée et en perspective, la surface supérieure d'un barillet, et un arbre agencé pour recevoir le sous-ensemble différentiel de la figure 7.

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

• the figure 1 shows, schematically, in section passing through its pivot axis, a barrel clockwork motor not forming part of the invention and which comprises a coaxial differential mechanism with balls allowing the visualization of the remaining power reserve at the level an indicator controlled by an output wheel which is the wheel serving as a basket for the differential balls;
• the figure 2 similarly represents a power reserve indicator based on the mechanism of the figure 1 , completed with reinforcement cogs for the transmission of movement between a ratchet and a board differential serving as the first input to the ball differential, the second input being constituted by the barrel itself;
• the figure 3 similarly represents an embodiment not part of the invention but close to the invention, with a power reserve indicator based on the mechanism of the figure 1 , completed with a planetary gear train for the transmission of movement between a ratchet and a differential board serving as the first input to the ball differential, the second input being constituted by the barrel itself;
• the figure 4 is a block diagram illustrating a watch comprising a movement incorporating a power reserve indicator, a motor, and a coaxial ball differential according to the invention;
• the figure 5 represents, similarly to Figures 1 to 3 , but more schematically, an embodiment not part of the invention but close to the invention, with a barrel clockwork motor comprising a differential coaxial ball mechanism, in which a ratchet directly forms the cover of the barrel;
• the figure 6 represents, similarly to Figures 1 to 3 , a partial view of another variant of power reserve indicator, according to the invention, comprising a differential sub-assembly removable in a single block;
• the figure 7 shows, schematically and in perspective, such a differential sub-assembly, seen from an upper side opposite to a lower side where the balls are projecting;
• the figure 8 shows, schematically and in perspective, the upper surface of a barrel, and a shaft arranged to receive the differential sub-assembly of the figure 7 .

Detailed description of preferred embodiments

The invention relates to a power reserve display device for a mechanical timepiece, in particular a watch, comprising at least one energy source constituted by a spring barrel.

Patent applications from the same applicant, CH709904 and EP2977828 describe a clockwork power reserve indicator for displaying the power reserve indication of a plurality of energy accumulators each comprising an indicator cooperating with an input of a differential mechanism that this indicator comprises power reserve, and including an output of this differential mechanism cooperates with a mechanism for displaying the total power reserve of the plurality of energy accumulators, at least two of the inputs of which are coaxial.

More particularly, in this prior art, the differential comprises a hub driving a carrier disc, which carries balls in contact with both a first input plate and a second input plate, which are idly mounted on this hub, under the action of friction imposed by one or more springs. The hub is also integral with an outlet in the form of a wheel which meshes with a deflection plate which has an input mobile, pivoting around another fourth pivot axis, this plate being coaxial and pivotally integral of a pinion which attacks an input board of a power reserve display mechanism, coaxial and pivotally attached to a shaft arranged to carry a display element such as a needle, disc, or the like.

The invention described below relates to various objects according to a common inventive step: an engine comprising a barrel, an additional mechanism designed for the transformation at low cost of such an engine to add to it the power reserve display function, or an autonomous power reserve mechanism comprising such a motor.

The invention is described only in the simple case of an engine with a single barrel, a person skilled in the art will know how to extrapolate it, in particular with the documents cited above, for a timepiece comprising several barrels.

In a first variant, the invention relates to a clockwork motor 10 comprising a barrel. This barrel is of conventional type, pivoting around a shaft 11, enclosing a spring mounted between the barrel and the shaft 11, which pivotally bears a ratchet 21 for driving the shaft.

The motor 10 comprises a differential 20, coaxial with the barrel along the axis D of pivoting of the barrel which is also the axis of the shaft 11, and of which a first inlet is driven indirectly by the ratchet 21, and of which a second inlet is the barrel. The output of this differential 20 is a pivoting output wheel 23, coaxial with the shaft 11, which is arranged, either to constitute a power reserve indicator, or else to drive a power reserve indicator mechanism 100, in particular and not limitatively by means of a gear train or the like.

And, in a preferred embodiment, since it is very economical, illustrated in the figures, this differential 20 comprises balls 25, which cooperate with a surface upper 13 of the barrel and with a lower surface 26 of a differential board 22. This differential board 22 is arranged to pivot on the shaft 11, is coaxial with it, and is connected to the ratchet 21 by a friction means 24 , and which is the first entry. These balls 25 cause in their rotation of the housings that comprises the output wheel 23 forming basket. This lower surface 26 is disposed on the side of the upper surface of the barrel.

More particularly, the barrel conventionally consists of a drum 14 provided with teeth and a cover 12 enclosing the spring together. Depending on the configuration of the barrel assembly, the ratchet 21 faces the cover 12 as visible in the figures, or respectively to the drum 14.

The first entry for winding is driven indirectly by the ratchet 21 and the second entry for disarming is constituted by the cover 12, or respectively by the drum 14. And the balls 25 cooperate, on the one hand with an upper surface 13 of the cover 12, or of the drum 14 respectively, and on the other hand with the lower surface 26 of the differential board 22.

More particularly, the friction means 24 is a spring disposed between the ratchet 21 and the differential wheel 22.

In a second variant, the invention relates to a power reserve indicator mechanism 100 for displaying the power reserve of a clockwork motor 10 comprising a barrel consisting of a drum 14 provided with toothing and d '' a cover 12 enclosing together a spring mounted between on the one hand the barrel and on the other hand a barrel shaft 11 around which the barrel pivots, the barrel shaft 11 being load-bearing and pivotally attached to a transmission ratchet 21 outside the barrel and facing the cover 12, or respectively to the drum 14. It is an additional mechanism, which suffices to add to an existing barrel assembly if it is predisposed (by an adequate machining of the 'barrel shaft 11), or add to an existing barrel assembly of which the barrel shaft 11 has previously been replaced by a shaft adapted to receive this power reserve indicator mechanism 100.

• une planche de différentiel 22, qui est agencée pour pivoter coaxialement à l'arbre 11, cette planche de différentiel 22 étant disposée entre :
  • d'un côté supérieur, un moyen d'entraînement par friction 24 agencé pour un entraînement relatif entre la planche de différentiel 22 et un rochet 21,

et, d'un côté inférieur,

• une roue de sortie 23 qui est agencée pour pivoter coaxialement à l'arbre 11, et qui constitue un panier de maintien de billes 25 que comporte encore le sous-ensemble,
• ces billes 25 étant agencées pour rouler entre une surface inférieure 26 de la planche de différentiel 22 et une surface supérieure 13 d'un couvercle 12, ou respectivement d'un tambour 14,

et où la roue de sortie 23 est agencée pour constituer ou entraîner un indicateur de réserve de marche 100 d'un moteur 10.This mechanism 100 then comprises a very small number of components, each of low unit cost. The mechanism 100 comprises a differential mechanism 20 with balls, which is coaxial with the barrel, and comprises a sub-assembly which is arranged to be interposed axially between a cover 12, or respectively a drum 14, and a ratchet 21. This sub -set includes:

• a differential board 22, which is arranged to pivot coaxially with the shaft 11, this differential board 22 being arranged between:
  • on an upper side, a friction drive means 24 arranged for a relative drive between the differential board 22 and a ratchet 21,

and, on the bottom side,

• an output wheel 23 which is arranged to pivot coaxially with the shaft 11, and which constitutes a ball retaining basket 25 which also comprises the sub-assembly,
• these balls 25 being arranged to roll between a lower surface 26 of the differential board 22 and an upper surface 13 of a cover 12, or of a drum 14 respectively,

and where the output wheel 23 is arranged to constitute or drive a power reserve indicator 100 of a motor 10.

Naturally, the power reserve indicator mechanism 100 can integrate a motor 10 as described above.

The transmission of movement from the ratchet 21 to the differential wheel 22 requires compliance with the direction of pivoting, and may require a reduction or reduction ratio: due to the principle of ball differential it is a reduction in one ratio of 2.

In a third variant, a non-limiting example of which is visible on the figure 2 , the power reserve indicator mechanism 100 comprises a plate 2, which carries the motor 10. And this plate 2 carries a gear train for the differential drive 30 meshing with the ratchet 21 and with a gear train for the differential gear 40 that carries also the plate 2 and which meshes with the differential board 22.

The differential drive return gear 30 comprises a differential drive return gear 32, which carries a differential drive return 31, which meshes directly with the ratchet 21. The toothing 33 of the differential drive return gear 32 meshes with the toothing 42 d '' a differential wheel return 41.

In an embodiment not part of the invention but close to the invention, visible on the figure 3 , the power reserve indicator mechanism 100 comprises a plate 2 carrying the motor 10: This plate comprises at least two pivots 60, each carrying a idler gear 61 of which a toothing 62 meshes, on the one hand with an external toothing which comprises the differential plate 22, and on the other hand with an internal toothing 210 which comprises a ratchet 21. This embodiment with planetary gear train is, however, more expensive than the third variant with intermediate reinforcement cogs.

The figure 5 illustrates, in a very simplified manner, insofar as most of the components which it comprises are similar to those set out above, another embodiment not forming part of the invention but close to the invention, but advantageous because reducing the axial size, in which the ratchet 21 directly forms the cover of the barrel, and there is naturally a clearance (not shown in the figure) between this ratchet 21 and the drum 14. The balls 25 then cooperate with an upper surface of the drum 14. This ratchet 21 has a toothing 211 which attacks the differential board by means of an ad hoc train. For example, on the figure 5 , the toothing 211 cooperates with a first toothing 72 of a ratchet gear 71, of which a second toothing 73 attacks a toothing 75 of a reversing gear 74, which also meshes with the toothing 220 of the differential board 22. The means friction 24 then bears directly on a plate 2. Naturally, the drive train by the drum 14 of the barrel must then be done in another peripheral zone of the barrel.

The figure 6 illustrates another variant, according to the invention, comprising a differential sub-assembly 50 removable in a single block.

This differential sub-assembly 50 is entirely assembled on a first shouldered ring 51, arranged to be mounted axially free on a bearing 112 of the shaft 11 on which it is threaded. A first external shoulder 52 of this first shouldered ring 51 carries the output wheel 23 of the differential, free to pivot relative to the first shouldered ring 51.

As before, the output wheel 23 forming a basket comprises, in housings 231, balls 25 which cooperate with the upper surface 13 of the drum 12 of the barrel, and with the lower surface 26 of a differential board 22. Preferably, these housings 231 are produced with a constriction at their lower orifice, on the side facing the drum 12, so as to be able to handle the sub-assembly 50 fitted without losing the balls 25. This constriction can be obtained during stamping of the output wheel 23, or else be produced by a light matting or the like. After positioning the output wheel 23 fitted with its balls 25 resting on the first external shoulder 52, the differential board is mounted 22 which is already driven out on a second shouldered ring 56, in abutment on a second external shoulder 58 which comprises this second shouldered ring 56. This second shouldered ring 56 is free to pivot on the first shouldered ring 51, in particular in the non-embodiment limiting of the figure 6 a bore 57 of the second shouldered ring 56 pivots freely on an external bearing 54 which comprises the first shouldered ring 51.

Naturally, the second shouldered ring 56 and the differential board 22 can also be produced in a single component, the important thing being to sufficiently separate the toothing of the ratchet 21 from that of the differential board 22. The second shouldered ring 56 allows above all to use a board 22 from stamping, much less expensive than a machined wheel.

The differential board 22 is supported on the balls 25.

The differential sub-assembly 50 is finally capped by the ratchet 21 which is driven out on the first shouldered ring 51, and in abutment on an upper bearing face 58 of the second shouldered ring 56.

At this stage, the differential sub-assembly 50 can be manipulated in one piece, and be returned if necessary, in particular by a robotic mounting means.

The shaft 11 advantageously comprises drive means 111, shown in a nonlimiting manner on the figure 8 by dishes, arranged to cooperate with complementary drive means 511 that comprises the first shouldered ring 51, as visible on the figure 7 , for their pivoting drive one by the other, and for reassembling the motor 10. Naturally, this pivoting drive can be carried out by any means known to those skilled in the art, directly or even indirectly via a key or the like.

We still see on the figure 6 a friction means 24, of the elastic washer type or the like, between the ratchet 21 and the plate 2.

The friction between the ratchet 21 and the second shouldered ring 56 carrying the differential board 22 which thus always constitutes the first input of the differential, the second input being constituted by the barrel drum 12.

The invention also relates to such an independent differential sub-assembly 50, arranged to be mounted on a clockwork shaft 11, which constitutes a removable sub-assembly in a single block and comprises a first shouldered ring 51, arranged to be mounted free axially on a span of a shaft 11 and integral in pivoting with this shaft 11, which first shoulder ring 51 carries, coaxially, an output wheel 23 mounted to pivot freely relative to the first shoulder ring 51, this output wheel 23 constituting a basket for a plurality of balls 25 projecting from a lower end of said differential sub-assembly 50 and arranged to roll on a surface of revolution of a mobile or of a barrel, this first shouldered ring 51 carrying, directly or indirectly, a differential board 22 also free to pivot on the first shouldered ring 51 and mounted as a friction bearing on the balls 25 on the side opposite their projecting end at the lower end, and a ratchet 21 being driven out on the first shouldered ring 51 so as to frictionally drive the differential board 22 .

The invention also relates to a timepiece movement 200 comprising at least one such motor 10, and / or at least one such power reserve indicator mechanism 100.

The invention also relates to a watch 300, or timepiece, comprising at least one such motor 10, and / or at least one such power reserve indicator mechanism 100.

In short, the integration of a ball differential directly on the barrel, coaxially, according to the invention, offers a useful horological complication, at an acceptable production cost, since it requires only limited transformations, and additions simple components in small numbers.

At the level of the barrel, it suffices to modify the tree. It is no longer necessary to add a pinion integral with the cover or the drum for driving the differential.

The gain in height compared to a standard differential is significant.

The saving of space in the plane is important, because the differential is coaxial with the barrel.

The cover (or the drum, depending on the arrangement) of the barrel acts directly as an entry for disarming.

The output wheel 23 of the differential cannot be directly driven through the transmission ratchet 21, in fact, the latter rotating in the same direction as the barrel, the output of the differential would only rotate in one direction. This is why, according to the invention, a gear train is incorporated to change the direction of pivoting. The transmission ratchet, integral with the barrel shaft, drives the differential plate through simple kinematics, in particular a gear train, with the interposition of an inverter to make up for the correct direction of pivoting: this is the object of the third variant with double gear train. The overall space saving remains, whatever the solution chosen, significant compared to the prior art.

Claims (5)

1. Timepiece power source (10) comprising a going barrel, pivoting about an arbor (11), containing a mainspring mounted between a drum (14) of said barrel and said arbor (11), which carries and rotates integrally with a ratchet wheel (21) for driving said arbor (11), said power source (10) including a differential gear (20) of which a first input is driven indirectly by said ratchet wheel (21) and a second input is said barrel, and whose output is a pivoting output wheel (23), coaxial to said arbor (11) and arranged to form or to drive a power reserve indicator (100), and wherein said differential gear (20) includes balls (25) arranged to drive housings of said output wheel (23) which forms a cage, and cooperating with an upper surface (13) of said barrel and with a lower surface (26), which is arranged on the side of said upper surface (13) of said barrel, of a differential plate (22), said plate (22) is arranged to pivot on said arbor (11), coaxially thereto, and is connected to said ratchet wheel (21) by a friction means (24) and forms said first input, characterized in that said differential gear (20) is a differential sub-assembly (50), which is removable in one piece and includes a first stepped ring (51), arranged to be mounted for free axial rotation on a bearing surface of said arbor (11) and to pivot integrally with said arbor (11), said first stepped ring (51) carries said output wheel (23) mounted for free rotation with respect to said first stepped ring (51), which also carries, directly or indirectly, said differential plate (22) which also rotates freely on said first stepped ring (51), said differential plate (22) bearing on said balls (25), and said ratchet wheel (21) being pressed onto said first stepped ring (51) for the friction driving of said differential plate (22).
2. Timepiece power source (10) according to claim 1, characterized in that said ratchet wheel (21) is external to said barrel, which includes a drum (14) provided with a toothing and with a cover (12), and is opposite to said cover (12) or respectively to said drum (14), and in that said differential gear (20) is arranged to be axially inserted between said cover (12), or respectively said drum (14) and said ratchet wheel (21).
3. Timepiece movement (200) including a plate (2) carrying a said power source (10) according to claim 1 or 2, characterized in that said plate (2) carries a first intermediate train (30) for driving the differential gear, which meshes with said ratchet wheel (21) and with a second intermediate train (40) for the differential gear, which is also carried by said bottom plate (2) and which meshes with said differential plate (22).
4. Timepiece movement (200) according to claim 3, characterized in that said plate (22) is arranged to pivot on said arbor (11), coaxially thereto, and is connected to said ratchet wheel (21) and to a bottom plate (2) by a friction means (24).
5. Watch (300) or timepiece including at least one power source (10) according to claim 1 or 2, or a timepiece movement (200) according to claim 3 or 4.

Images