EP1995650A1 - Timepiece movement comprising a karrusel - Google Patents

Abstract

The movement has a balance and a gear-train for transmitting the energy stored in a barrel to an escapement wheel. The gear-train has an intermediate wheel (23) kinematically connected to the barrel by a portion of the gear and kinematically connected to the escapement wheel by another portion of the gear. The latter portion and the balance are mounted in a rotary cage (16) kinematically connected to the movement and coaxially rotated about the intermediate wheel at a speed different from speed of the intermediate wheel. The movement imposes speed of one revolution per minute to the cage.

Description

The present invention generally relates to mechanical watch movements in which the portion of the finishing train which kinematically links an intermediate wheel to the escape wheel is mounted on a rotary platform which also carries the escapement and the balance, said platform shape being further driven by the movement to rotate about the axis of the intermediate wheel at a speed different from the speed of the intermediate wheel.

We already know watch movements that correspond to the definition above. The patent document CH 7965 in particular describes such a movement with reference to drawings, one of which is reproduced in the figure 1 , attached to this document. The described movement comprises a finishing which has been shown only the last two mobiles. This is the mobile formed by the average pinion and the average wheel (respectively referenced G and H), and the mobile formed by the pinion and the second wheel (respectively referenced A and C). The document specifies that the second wheel (or intermediate wheel) C causes the exhaust (not shown) in a known manner. On the other hand, the exhaust and the beam E are mounted on a platform F. The platform F has on its underside a thick cylindrical pin B which is inserted to rotate in an opening of a board P. The cylindrical pivot B is hollow and is shaped so as to pass the axis of the second mobile, so that the platform F and the second wheel rotates about the same axis. Finally, the average gear G is designed to drive the platform F in rotation, via a wheel D, pierced in the middle and screwed to the platform, concentrically to the axis of rotation thereof.

In the example described by this prior document, the average wheel H is driven in a fairly conventional manner at the speed of one revolution in 7 ½ minutes. The average G pinion has seven times less teeth than the D wheel with which it engrains, the platform F thus performs a turn every 52 ½ minutes. On the other hand, the pinion of second A has 7 ½ times less teeth than the wheel of average H. The pinion of second A therefore classically performs exactly one revolution per minute. As the rotational speed of the wheel of second C is determined by the escapement, which turns itself, with the platform F, in the same direction as the wheel of second C, the frequency of the beam E must be decreased about 2% to account for the speed of platform F.

The skilled person will have recognized in the foregoing description a carousel. Reading this description, it is understood that the mechanism of the carousel is quite different from that of the vortex. Indeed, as in an ordinary watch, with a carousel, the energy of the barrel is transmitted to the escape wheel via the second wheel. The drive of the platform by the movement is provided by an additional gear, and if this gear is disengaged, the watch can continue to operate while the platform is no longer running.

According to the book "The watch: principles and methods of manufacture" (pages 298-9 ), the carousel compensates as well as the vortex equilibrium balancing defects. In addition, it is easier to produce and produce in quantity. However, for watchmakers and collectors, the tourbillon is more pleasant to watch. An object of the present invention is therefore to provide a watch movement equipped with a carousel that has the same aesthetic qualities as a tourbillon. It achieves this goal by providing a watch movement according to claim 1.

According to the present invention, when the movement is running, the cage rotates at a speed of one revolution per minute. The implementation of this technical feature is not self-evident. Indeed, the second wheel of the carousels of the prior art also performs one revolution per minute. However, if the second wheel and the cage were running at the same speed, the escape wheel would not be driven. Thus, according to the present invention, the speed of the second wheel is not one revolution per minute. This wheel is not strictly speaking a wheel of seconds, but a false-second wheel or, more simply, an intermediate wheel. In addition, since the speed of this intermediate wheel is not one revolution per minute, it can not be used to carry the seconds indicator of a timepiece. However, in a timepiece equipped with a movement according to the present invention, the cage may advantageously be visible on the dial side and itself bear means for indicating the seconds.

It may be tempting to summarize appended claim 1, by saying that it defines a carousel characterized in that it is intended to rotate at a speed of one revolution per minute. However, it should be noted that watchmaking literature contains two incompatible definitions for a carousel. The present application uses the term carousel in its traditional sense which includes all the features of the preamble of claim 1. However, the book "Theorie d'horlogerie" gives another definition for a carousel. According to this more recent definition, a carousel is simply a vortex in which the balance is off-center with respect to the axis of rotation of the cage. Obviously, based on this second definition, a carousel rotating at a speed of one revolution per minute is a thing well known to those skilled in the art.

• la figure 1, reproduite du document de brevet CH 7965 , est une vue schématique en coupe du rouage d'un carrousel de l'art antérieur ;
• la figure 2 est une vue en plan du rouage entraînant la cage du carrousel d'un mouvement horloger selon un mode de réalisation particulier de la présente invention ;
• la figure 3 est une vue schématique en coupe selon A-A de la figure 2 ;
• la figure 4 est une vue en plan du rouage entraînant l'échappement du mouvement horloger de la figure 2 ;
• la figure 5 est une vue schématique en coupe selon B-B de la figure 4 ;
• la figure 6 est une en plan du rouage complet du carrousel de la figure 2 ;
• la figure 7 est une vue schématique en coupe illustrant une variante de réalisation de la cage du carrousel.

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

• the figure 1 , reproduced from the patent document CH 7965 , is a schematic sectional view of the workings of a carousel of the prior art;
• the figure 2 is a plan view of the train driving the carousel cage of a watch movement according to a particular embodiment of the present invention;
• the figure 3 is a schematic sectional view along AA of the figure 2 ;
• the figure 4 is a plan view of the gear train causing the escape of the watch movement from the figure 2 ;
• the figure 5 is a schematic sectional view along BB of the figure 4 ;
• the figure 6 is a plan of the complete carousel of the carousel of the figure 2 ;
• the figure 7 is a schematic sectional view illustrating an alternative embodiment of the carousel cage.

The drive train of the cage of a carousel, which is represented in figures 2 and 3 , is a cogwheel type finishing. Thus, it comprises a center wheel 3 driven by a barrel (not shown) and conventionally one turn per hour. The axis 5 of the center wheel is intended to carry a minute hand. The wheel also comprises a moving average comprising a pinion of average 7 and a wheel of average 9, and a carousel wheel 17 integral in rotation with the cage of the carousel 16. The carousel wheel 17 is driven indirectly by the wheel of average via two intermediate mobiles, namely a first intermediate mobile formed pinion 11 and the wheel 13 and a second intermediate mobile referenced 15 and serving as a reference. By analogy with a traditional finishing, the mobile 11, 13 is hereinafter called "mobile inter second".

It will be understood from the foregoing that, in the present example, the carousel wheel 17 being separated from the center wheel 3 by an odd number of mobiles, these two wheels rotate in the same direction. On the other hand, the gear ratio between the average pinion 7 and the center wheel 3 is 11 ¼, while the gear ratio between the second pinion inter 11 and the average wheel 9 is 9. _^3/5, and the gear ratio between the carousel wheel 17 and second wheel 13 is inter _^5/9. It can therefore be calculated that the carousel 16 rotates 60 times faster than the center wheel. He thus accomplishes 1 turn per minute.

We can still see in the figures that the carousel 16 carries the balance 19 and the exhaust mechanism. In the present example, the escape mechanism is of the conventional type. It comprises in particular an escape wheel 27 which is visible in particular on the figure 2 (the escape mechanism is not represented in the figure 3 ).

The figures 4 and 5 represent the cogwheel that connects the barrel (not shown) to the escape wheel. figures 4 and 5 is also of the type finishing is sharing some of its motives with the wheels of figures 2 and 3 . The gear train driving the exhaust comprises the center wheel 3, the average wheel 7, 9, and the escapement consisting of an exhaust pinion 25 and the escape wheel 27. The exhaust pinion is driven indirectly by the average wheel 9 via an intermediate mobile formed pinion 21 and the wheel 23. By analogy with a traditional finishing, the pinion 21 and the wheel 23 are respectively called hereinafter pinion wheel and "false second ".

According to the present invention, one of the mobiles of the exhaust drive train is arranged to rotate coaxially with the carousel wheel 17 and thus also with the cage of the carousel 16. As can be seen on the figure 5 particular, in this example, it is the false second mobile 21, 23 which coaxially rotates with the carousel. On the other hand, as has already been said, the escapement 25, 27 and the balance 19 are mounted in the cage 16 and thus rotate with it.

We have already seen that the gear ratio between the average pinion 7 and the center wheel 3 is 11 ¼. On the other hand, the gear ratio between the false second pinion 21 and the third wheel 9 is 10 _^2/3. It can therefore be calculated that the false second wheel rotates 120 times faster than the center wheel. In addition, a single mobile separates the false second mobile 21, 23 from the center wheel 3. Under these conditions, the false second wheel 23 rotates in the same direction as the center wheel, and therefore also rotates in the same direction. meaning that the carousel cage.

According to the present invention, the carousel cage rotates at a speed of one revolution per minute. Given the gear ratios used in this example, it can be deduced that the center wheel does one revolution per hour. The speed of the axis 5 of the center wheel is therefore adequate to carry a minute hand. It also follows from the selected gear ratios that the false second wheel 23 accomplishes two revolutions per minute. This last wheel rotating in the same direction as the cage 16, it follows that in the present example, the speed of the false second wheel 23 relative to the cage is one revolution per minute.

It will be understood from the foregoing that an advantageous consequence of the gear ratios used in the present example is that the balance and the escapement can operate at the same frequency as in a usual clockwork movement. Indeed, the exhaust being mounted in the cage, it must therefore regulate the false second wheel at the usual speed of one revolution per minute. With this feature, it is possible to use a standard pendulum and exhaust to achieve the watch movement of this example. One can for example choose a balance 19 with a frequency of 3 Hz, a wheel exhaust having fifteen teeth, and a gear ratio of twelve between the exhaust pinion 25 and the false second wheel 23.

As can be seen on the figure 5 in particular, in the present example, the arrangement of the cage is conventional. This cage is pivotally mounted between the bearing 31 of the cage bridge 33 and the bearing 35 of the barrel bridge 37. figure 5 allows to appreciate another feature made possible by the present invention. It can be seen that the balance 19 is arranged coaxially with the cage of the carousel 16. Although this arrangement is aesthetically advantageous, it could cause some problems. Indeed, the balance shaft extends in the extension of the mobile (false) second 21, 23, between the dial (not shown) and the latter. It will be understood that, under these conditions, it is problematic to extend the axis of the second mobile to bring to it a visible needle dial side. However, as according to the present invention, it is the carousel cage 16 which rotates at the speed of one revolution per minute, the latter can be substituted for the second mobile to carry the seconds indicator.

The figure 7 represents a carousel "steering wheel" which is an alternative embodiment of the carousel of the previous figures. According to this variant, the wheels and the escapement are identical to those described in relation to the Figures 2 to 6 . Comparing the figure 7 to the figure 5 it can be seen that a ball bearing 41 has taken the place of the bearing 31 in the cage bridge 33. As the bearing 31 of the figure 5 , the core 43 of the bearing shown in FIG. figure 7 is traversed by a vertical cylindrical opening for passing the false second mobile 21, 23. Also visible on the figure 7 that the outer ring of the ball bearing is fixed in the cage bridge 33 while the core 43 carries the carousel wheel 17 and thus also the cage as a whole. With this arrangement, the barrette bridge 37 ( figure 5 ) and the step 35 can be deleted. Thus, in this variant, the cage is mounted on a single pivot supporting it by the base. In addition, the cage is completely free on the top. The carousel therefore gives the impression of flying above the movement, hence the name "flying carousel".

It will be understood that various modifications and / or improvements obvious to one skilled in the art can be made to the embodiment which is the subject of the present description without departing from the scope of the present invention defined by the appended claims. In particular, the skilled person can modify the wheels by removing or adding mobiles or by changing gear ratios. The only constraint is that the carousel wheel 17 must rotate in the same direction and at a speed 60 times greater than the axis of minutes 5. It is important to understand in particular that the speed of the intermediate mobile 21, 23 relative to the cage 16 does not need to be equal to one revolution per minute. The present invention does not impose, in fact, any constraint as regards the speed of the intermediate wheel 23. The intermediate mobile can, as in the preceding example, turn faster than the cage in the same direction as that -this. However, it can just as well turn slower than the cage in the same direction as this one, or even turn in the opposite direction to that of the cage. The skilled person will not encounter any problem to achieve these variants of carousels. Indeed, it knows how to manufacture rockers and / or escapements to regulate the rotation of a wheel at any speed different from one turn per minute. Moreover, he knows how to make escapements turning in one direction or the other. In this respect, it is worth noting that if the wheel 23 rotates in the same direction, but slower than the cage, its speed relative to the cage is negative. In other words, relative to the cage 16, the wheel 23 rotates in the opposite direction.

On the other hand, according to another embodiment of the present invention having some similarities with the vortex which is described in the patent document EPO 973'076 , the mobile of (false) second 21, 23 meshing with the exhaust could be carried by the cage 16 in the eccentric position in the manner of a satellite. Under these conditions, instead of being coaxial with the false second mobile, the cage would be arranged to rotate about the axis of another intermediate mobile, for example a mobile (not shown in the figures) interposed between the mobile of average 7, 9 and the false seconds mobile 21, 23. The gear ratios could for example be chosen so that the intermediate mobile rotates in the same direction as the cage but a little slower than this one (Concretely, the intermediate mobile could for example include a large pinion of 20 teeth arranged to mesh with the wheel 9, so that the mobile is driven at a speed of 54 revolutions per hour). Under these conditions, relative to the cage which performs 60 revolutions per hour, the wheel of the intermediate mobile would rotate at a reduced speed in the opposite direction (at the speed of 6 revolutions per hour, in the present example). The gear ratio between the intermediate mobile and the false second mobile 21, 23 would then be determined so that the rotational speed of the false second wheel 23 relative to the cage is adapted to the rate of escape. used (the wheel of the intermediate mobile could for example have 90 teeth and the false second pinion 21, nine teeth). It will be understood in this new example, relative to the cage, the false second wheel 23 rotates in the direction of clockwise, which allows to use a rotating exhaust in the usual direction (the same direction as in the first example).

According to a variant of this last embodiment of the present invention, instead of turning slightly slower than the cage, the mobile interposed between the mobile of average 7, 9 and the false second mobile 21, 23 could turn slightly faster than the cage. Under these conditions, relative to the cage, the false second wheel 23 would turn in the opposite direction of the clockwise. As we have seen, this However, this characteristic does not represent a real problem for those skilled in the art.

Claims (9)

Watch movement comprising a barrel, an escapement comprising a wheel and an escape pinion (27, 25), a rocker arm (19) and a gear train designed to transmit energy stored in the barrel to the escape wheel, said wheel having an intermediate wheel (23), kinematically connected to the cylinder by a first part of the train, and kinematically connected to the escape wheel (27) by a second part of the train, the second part of the wheel, and the exhaust and the balance, being mounted in a rotary cage (16) kinematically connected to the movement and designed to rotate coaxially around said intermediate wheel (23) at a speed different from the speed of said intermediate wheel; characterized in that the movement is provided to impose a speed of one revolution per minute on the cage (16). Watch movement according to Claim 1, characterized in that the cage (16) is designed to rotate in the direction of rotation of the hands of a watch and that the cage still bears means indicating the seconds. Clock movement according to claim 2, characterized in that said intermediate wheel (23) is provided for turning in the direction of clockwise at a speed greater than the rotation speed of the cage (16). Clock movement according to claim 1, 2 or 3, characterized in that said intermediate wheel (23) meshes directly with the exhaust pinion (25). Clock movement according to claim 2, characterized in that said intermediate wheel (23) is designed to rotate in the same meaning that the cage at a speed lower than the rotational speed of the cage. Clock movement according to claim 5, characterized in that the second part of the train comprises a mobile interposed between said intermediate wheel and the exhaust pinion, said mobile being carried by the cage (16) in the eccentric position. Watch movement according to one of the preceding claims, characterized in that the rocker (19) is arranged to oscillate coaxially with the cage (16). Clock movement according to one of the preceding claims, characterized in that the cage (16) is mounted on a single pivot (41) supporting the cage (16) by the base, the cage being completely free on the top. Clock movement according to claim 9, characterized in that said pivot comprises a ball bearing (41).

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