EP2391926B1 - Timepiece movement - Google Patents

Description

Technical area

The present invention relates to a watch movement comprising a frame carrying a barrel arranged to maintain the oscillations of a mechanical oscillator via a finishing train. Conventionally, the barrel comprises a drum, housing a barrel spring whose one end is engaged with a barrel shaft pivotally mounted in two bearings, at least one of which is carried by the frame, the drum defining a first level in the direction of the thickness of the watch movement. More particularly, the finishing train comprises a first mobile arranged in engagement with a transmission member integral in rotation with the barrel shaft.

State of the art

In general, the cylinder outlet is provided by its drum, which has a toothing meshing with a first mobile of the finishing train adjacent to the drum.

However, a construction of the type mentioned above is disclosed in the patent EP 1 582 943 B1 which concerns a watch movement in which three barrels are mounted in series to provide a significant power reserve.

In this movement, two barrels are mounted coaxial having their respective springs connected to each other via a common barrel shaft. A first of the two barrels has a drum having a toothing by which the two springs can be recharged from a winding. The third barrel is disposed laterally to the first two and has a drum having a toothing arranged in engagement with the toothing of the drum of the second of the coaxial barrels. Therefore, the output of this third barrel, to maintain the oscillations of a mechanical oscillator movement, is formed from its shaft. The latter is integral in rotation with a transmission wheel having a peripheral toothing whose characteristics are similar to those of the drum of the third barrel.

Thus, the transmission of the force provided by the barrel springs is carried out conventionally to a first mobile of a finishing train, adjacent to the third barrel and, a pinion is arranged in engagement with the transmission wheel.

The fact of having two barrels superimposed in the movement induces a constraining increase in the thickness of the corresponding movement, with reference to a movement comprising only one barrel. Also, this patent proposes to use only a third barrel disposed laterally to the first two, to leave free a certain volume in superposition of the third barrel, whose thickness is slightly less than the thickness of a barrel. Such a construction provides a comfortable power reserve while having the freedom to provide a complication whose mechanism can be arranged in the space left free.

However, it should be noted that this solution, consisting in increasing the volume of the watch movement to make space available, is not suitable for the realization of timepieces with significant power reserve but thin.

The patent CH 51982 proposes a solution to a single barrel in which the energy of the mainspring is transmitted, via the barrel shaft, to a first mobile of the finishing gear rotatably mounted on the frame of the movement along an axis of rotation. superimposed on the barrel drum in the direction of the thickness of the movement to define a second level.

However, the construction proposed in this document is not satisfactory from the point of view of stability, especially in case of shocks. Indeed, the barrel drum is pivoted directly on the barrel shaft and simply rests in a seat in a plate of the movement. Thus, in case of shock, the drum can hit the barrel shaft and adversely affect the accuracy of operation of the oscillator.

Disclosure of the invention

A main object of the present invention is to overcome the drawbacks mentioned above, by proposing a watch movement with a comfortable power reserve while offering dimensions. and ensuring smooth and stable transmission of the barrel spring force to the gear train, ensuring better movement in conventional constructions, even in the event of shocks.

Another object of the present invention is to provide such a movement in which space is kept available to allow the addition of a possible complication mechanism.

For this purpose, the present invention more particularly relates to a watch movement as defined in claim 1.

Thanks to these characteristics, the diameter of the barrel can be enlarged with reference to a conventional construction, allowing to accommodate a spring of greater development to increase the power reserve of the movement, while preserving the maximum gear train finishing disturbances which could have their origin in inadvertent movements of the barrel drum, especially in case of shocks.

According to an advantageous embodiment, the two bearings of the barrel shaft are carried by the frame of the movement, possibly being disposed on either side of the drum. In this case, the barrel shaft is completely isolated from its drum and the movements that would present the latter in such a case would not be transmitted to the shaft and thus to the gear train, unlike the constructions of the prior art.

According to the invention, the frame comprises an annular shoulder whose inner periphery is integral with a bearing of the barrel shaft and the outer periphery is integral with the bearing of the barrel drum.

In particular, it can be provided that the bearing of the barrel drum has the shape of a ring comprising at least one sliding surface on which slides a surface of the barrel drum.

These features advantageously make it possible to obtain a relatively compact construction while ensuring a good quality of rotation of the shaft and the barrel drum.

Furthermore, the present invention also provides that the finishing gear comprises additional mobiles essentially disposed in the second level so as to release the useful space in the first level between the barrel and the mechanical oscillator. This useful space can thus be used to house a complication mechanism.

According to a preferred embodiment, the first mobile is a center mobile on which pivots at least one drive member intended to be integral with a central body for indicating a time information.

Thanks to these characteristics, the barrel can extend beyond the center of the movement and offer a significant power reserve. In addition, such a construction can be implemented with a conventional finishing gear in direct contact with the barrel outlet, in other words without requiring the addition of intermediate springs, sources of yield loss.

The present invention also relates to a timepiece equipped with such a watch movement.

Brief description of the drawings

• la figure 1 représente une vue en perspective simplifiée, du côté platine, d'un mouvement horloger selon un mode de réalisation préféré de la présente invention;
• la figure 2 représente une vue en coupe simplifiée suivant la ligne brisée II-II de la figure 1;
• la figure 3 représente une vue en perspective simplifiée et partiellement éclatée, du côté ponts, du mouvement horloger de la figure 1, et
• la figure 4 représente une vue en perspective simplifiée et partiellement coupée d'un mouvement horloger selon une variante de réalisation de la présente invention.

Other features and advantages of the present invention will appear more clearly on reading the detailed description of a preferred embodiment which follows, made with reference to the accompanying drawings given by way of non-limiting examples and in which:

• the figure 1 represents a simplified perspective view, on the platinum side, of a watch movement according to a preferred embodiment of the present invention;
• the figure 2 represents a simplified sectional view along the broken line II-II of the figure 1 ;
• the figure 3 represents a simplified and partially exploded perspective view, on the bridge side, of the watch movement of the figure 1 , and
• the figure 4 represents a simplified perspective view and partially cut a watch movement according to an alternative embodiment of the present invention.

Mode (s) of realization of the invention

The figure 1 represents a simplified perspective view, on the platinum side, of a watch movement according to a preferred embodiment of the present invention.

This watch movement comprises a barrel 1 housing a mainspring (numerical reference 2, on the figure 2 ) connected to a barrel shaft 4 at a first end thereof and to a barrel drum 5 at its second end. The barrel is further closed by a lid 6, driven on the drum, while the latter is provided with a toothing 8 at its periphery.

The present invention provides that a transmission member is mounted on the barrel shaft being rotationally integral therewith. This transmission member has the shape of a wheel 10 on the figure 1 .

The transmission wheel 10 is arranged in engagement with the pinion (reference numeral 12 on the figure 2 ) a center wheel 13 whose wheel 14 is engaged with a pinion 15 of average. A wheel of average 16, integral in rotation with the pinion 15, is arranged in engagement with the pinion (reference numeral 18 on the figure 2 ) of a mobile seconds 19 whose wheel 20 is engaged with the pinion 21 of an escape wheel 22. The escape wheel cooperates, in a conventional manner, with an anchor 23 arranged in kinematic relationship with a pendulum 24 forming a mechanical oscillator with a hairspring 25.

Thus, apart from its particular arrangement, the finishing gear train which has just been described makes it possible, typically, to transmit the energy stored by the mainspring to the mechanical oscillator of the watch movement in order to maintain the oscillations thereof.

The figure 2 represents a sectional view of the watch movement as described in connection with the figure 1 , made along the line II-II passing through the axes of the different motions of the movement.

This view makes it possible to better illustrate the advantage provided by the structure according to the present invention in terms of size in the watch movement.

Indeed, it is clear from the figure 2 that the barrel 1 defines a first level in the direction of the thickness of the movement while the center mobile 13 is superimposed on it by defining a second level. In addition, it also appears that the other mobiles of the work train are essentially located in the second level while the mechanical oscillator is located partly in the first level and partly in the second level.

Thanks to this particular arrangement of the mobiles of the work train, a useful space is released in the first level, that is to say on the bridge side, between the cylinder and the balance spring to possibly allow the addition of a mechanism of complication (not shown) such as a chronograph mechanism or display phases of the Moon.

In addition, the watch movement as shown is intended, by way of non-limiting illustration, to cause a central referral indicating the current time by mounting the corresponding drive members (floor and hour wheel, not visible) on the center mobile tree. So, we see on the figure 2 that the structure of the movement according to the present invention allows the use of a cylinder of large radius, capable of housing a mainspring such that the movement can have a large power reserve, which can extend especially beyond- beyond the center of the movement, in contrast to conventional center display movements.

Moreover, the particular assembly of the barrel 1, according to the present invention, is also visible in detail on the figure 2 .

A first end of the barrel spring 2 is secured to a plug 27 while its second end is integral with the barrel drum 5.

The barrel shaft 4, carrying the transmission wheel 10, is mounted between two bearings 28, 29, or stones, driven into elements of the frame, respectively a plate (not shown) and a barrel bridge 30. Such a structure guarantees excellent regularity in the meshing of the transmission wheel 10 with the pinion 12 of the center wheel 13 and therefore a good walk of the watch movement.

The plug 27 is mounted coaxially with the barrel shaft 4 so as to drive it in rotation throughout the development of the barrel spring.

The suspension of the barrel drum 5 is ensured by the cooperation of its center with first and second rings 32, 33, integral with the barrel bridge 30. The drum is retained axially, in one direction, by the first ring 32 and, in the other direction, by the second ring 33.

The first ring 32 could, alternatively, be integral with the drum or be omitted. In the latter case, it would be possible to reduce the thickness of the second ring 33 in such a way that the axial retention of the drum is ensured, on the one hand, by the second ring 33 and, on the other hand, directly by the bridge of barrel 30, without departing from the scope of the invention.

The second ring 33 is positioned on the barrel bridge 30 by means of an annular shoulder 35, simultaneously forming a housing for a bearing 29 of the barrel shaft 4, being held in place by means of screws 36, illustrative non-limiting.

Thanks to these particular characteristics, a good positioning of the barrel drum 5 is guaranteed and any defect of positioning, dimensioning or in the movement of the barrel drum has no impact on the movement of the movement since the drum and the Barrel shaft are mounted on the movement frame independently of each other. In addition, the suspension of the barrel is improved, in particular by reducing the risk of flapping and in case of shock. The construction proposed for the suspension of the cylinder also has a remarkable compactness with reference to the efficiency obtained.

Of course, a winding mechanism is provided for charging the mainspring, of which only the winding stem 38 has been shown in the figures for clarity. A conventional stop device, of the type ratchet, is also provided in the winding mechanism to prevent a discharge of the mainspring when the winding stem is not actuated by a user to recharge. It should be noted that given the particular structure of the watch movement according to the present invention, in particular the fact that the barrel output function is provided by its shaft, the winding mechanism is arranged to reload the barrel spring by the intermediate cylinder drum, more precisely by its teeth 8. Similarly, the stop device is arranged to prevent the barrel drum to rotate in the direction of rotation opposite to the direction corresponding to the load of the mainspring.

The figure 3 represents a simplified and partially exploded perspective view, on the bridge side, of the watch movement of the figure 1 , and illustrates a preferred construction detail.

More specifically, it appears from figure 3 that the bung 27 has two lugs 40 intended to cooperate with a disk 41 of the barrel shaft in which two flats 42 have been formed. Thus, the bung 27 and the barrel shaft 4 have between them a certain free angular clearance, that is to say when the barrel spring is not in place or is completely discharged. In normal operation of the movement, the lugs are disposed in abutment against the flats of the barrel shaft to drive the latter in rotation. Furthermore, the expected angular clearance limits the risk of damage to the gear train in case of rupture of the mainspring.

It will also be noted that the disassembly of the barrel 1 is simplified thanks to this construction. Once the barrel bridge 30 has been removed, the barrel 1 can simply be pulled out of motion with the plug 27, as shown in FIG. figure 3 , while its shaft 4 remains housed in the bearing 29 which is arranged in the plate, the transmission wheel remaining in engagement with the center wheel 13.

The figure 4 represents a view, in simplified perspective and partially cut, illustrating an alternative embodiment of the watch movement according to the present invention.

According to this variant embodiment, the mounting of the barrel 1 is reversed with respect to the embodiment of the preceding figures. Indeed, the barrel drum 5 is located on the platen side while a barrel bridge 43, interposed between the drum and the transmission wheel 10, is provided to ensure the suspension of the barrel in a manner similar to what has been has been previously described in relation to the ring 33. Advantageously, the barrel bridge 43 may also comprise a bearing for the plug 27.

Another significant difference with reference to the previous embodiment lies in the mounting of the barrel shaft 4. The latter is pivoted, on the one hand, in a stone 29 housed in the plate and, on the other hand, in a stone 44 housed in the lid 6 of the barrel.

Such a structure makes it possible to modify the typical location of the barrel bridge to place it between the barrel and the plate and thus make the barrel completely visible from the bottom of a timepiece that would be equipped with the corresponding movement, offering a completely new aspect to this timepiece.

Of course, if the insulation of the barrel shaft is here less effective than in the case of the first embodiment of the Figures 1 to 3 , the fact that the shaft is guided by a bearing mounted on an element of the frame of the movement still allows to reduce the impact of untimely movements of the drum on the smooth running of the mechanical oscillator movement. Note that it is possible, as an alternative to the illustrated construction, to provide that the second bearing of the barrel shaft housed in the cover can be mounted elsewhere, in a frame member, on the same side as the first bearing. reference to the drum. This would provide a level of insulation of the barrel shaft equivalent to that of the first embodiment

The foregoing description attempts to describe a particular embodiment by way of non-limiting illustration and the invention is not limited to the implementation of certain particular features which have just been described, for example the type of exhaust illustrated and described. Note also that the present invention can also to be implemented in connection with a train of the type with large average, with the same advantages, whether a time information display is provided in the center or not.

Those skilled in the art will not encounter any particular difficulty in adapting the content of the present disclosure to their own needs and implementing a clockwork movement that is different from the embodiment described here, but presenting a first mobile of the finishing gear superimposed on the barrel without departing from the scope of the present invention. It will be noted, for example, that the adaptation of the present teaching with a view to the construction of a watch movement in which, for example, two adjacent barrels are mounted in series, by means of their drums, will not pose any particular difficulty to the skilled person.

Claims (9)

1. Timepiece movement comprising a frame (30, 43) bearing a barrel (1) designed to sustain the oscillations of a mechanical oscillator (24, 25) through a geartrain (12, 13, 14, 15, 16, 18, 19, 20), said barrel comprising a drum (5) housing a mainspring (2) a first end of which is connected to a barrel arbor (4) pivot mounted in two bearings (28, 29) at least a first bearing (29) of which is borne by said frame, said drum defining a first level in the direction of the thickness of the timepiece movement, said geartrain comprising a first wheel (13), arranged in mesh with a transmission member (10) that rotates as one with said barrel arbor, said first wheel (13) being mounted to rotate on the frame about an axis of rotation superimposed with said barrel drum (5) in the direction of the thickness of the timepiece movement in order to define a second level,
   characterized in that said barrel drum (5) is also pivot mounted in a second bearing (33) of said frame (30) so as to be suspended from the latter, said frame (30) comprising an annular shoulder (35) the internal periphery of which is secured to said first bearing (29) of said barrel arbor (4) and the external periphery of which is secured to said second bearing (33) of the barrel drum (5).
2. Timepiece movement according to Claim 1, characterized in that said bearing of the barrel drum takes the form of a ring (33) comprising at least one sliding surface over which one surface of the barrel drum (5) slides.
3. Timepiece movement according to any one of the preceding claims, characterized in that said geartrain comprises additional wheels (15, 16, 18, 19, 20) essentially arranged in said second level so as to free up useful space in said first level, between said barrel (1) and said mechanical oscillator (24, 25).
4. Timepiece movement according to any one of the preceding claims, characterized in that said first wheel is a centre wheel (13) on which there pivots at least one drive member intended to be secured to a central member indicating time information.
5. Timepiece movement according to any one of the preceding claims, characterized in that said frame comprises a plate and at least one bridge (30, 43), said transmission member (10) being arranged on the plate side with reference to said barrel (1).
6. Timepiece movement according to any one of the preceding claims, characterized in that a boss (27) is secured to said first end of the main spring (2), said boss having at least one lug (40) engaging for the purposes of rotation with an abutment surface (42) borne by said barrel arbor (4).
7. Timepiece movement according to any one of the preceding claims, characterized in that it comprises a rewinding mechanism (38) designed to rewind said main spring (2) by rotating said barrel drum (5).
8. Timepiece movement according to any one of the preceding claims, characterized in that said bearings (28, 29) of said barrel arbor (4) are borne by said frame and are arranged on either side of said barrel drum (5).
9. Timepiece comprising a timepiece movement according to any one of the preceding claims.

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