HK1171269B - Timepiece movement - Google Patents

Description

Technical field

The present invention relates to movement of a watch part of the type incorporating a power source, a time base with several swings, means of connecting the power source to the time base, and mobiles arranged to carry time display devices.

State of the art

To further reduce position sensitivity, some watches are equipped with two swings whose swings axes are not parallel. A solution of this type is described in patent application WO 2005/043257. The movements equipped with such watches are of great complexity. Furthermore, the volume occupied by the swings and the power consumption in the two swings can be varied, as can the two power consumption in the reference position WO 2008/10182. The demand for such swings allows for a partial compensation of the weight of the swings, which varies in relation to the average angle of the swings.

One purpose of the present invention is to propose a movement for a watch part which is particularly sensitive to changes in position.

The Commission shall adopt implementing acts laying down the rules for the application of this Regulation.

The present invention relates to a movement for a watch part which contains a power source, a time base, means of connecting the power source to the time base, and mobiles arranged to carry time display means.

Thus, regardless of the position of the movement, the average position of the axes of the pendulums is constant.

The regular polyhedron is defined by one or more planes parallel to each other and perpendicular to the axes of the pendulum.

In a first variant, the said time base includes four oscillators and the said polyhedron is a regular tetrahedron.

In a second variant, the said time base consists of three swings and the said polyhedron is a cube.

In a first embodiment, the energy source comprises at least one barrel per balance. Furthermore, the barrel is connected to the balance by a gear train. This movement also includes a differential type structure connecting each gear train to the moving parts.

In a second embodiment, the movement also has a differential type structure and the energy source comprises at least one barrel which is kinematically connected to the said movers and the swingers by the said differential type structure.

It is advantageous for the means of displaying time to rotate around an axis which makes a non-perpendicular angle with the axes of the swings.

The present invention will be better understood by reading the following description, given as an example and made with reference to the drawings in which: Figures 1 and 2 show schematically the general structure of the variants in which the movement is equipped with four and three swings respectively; Figures 3 and 4 show schematically the systems of the differential type equipping the movements shown in Figures 1 and 2 respectively; Figure 5 is a variant of the differential system in Figure 4; and Figure 6 shows a gear which can allow a change in the working plane of a gear train.

The method of implementation of the invention

The movement 10 is a truncated pyramid which, in the absence of truncation, would have four equilateral triangular faces, forming a regular tetrahedron. The movement 10 is composed of four sets A, B, C and D, represented schematically by two circles, illustrating a barrel 12 and a pendulum 16, respectively, connected by a line, illustrating a finishing gear 14.

Movement 10 also shows on mobiles such as a road and a crankshaft not shown in the drawing, means of displaying time formed by hands 18 as shown in Figure 1.

In particular, as referred to in Figure 3, this structure 20 comprises two spherical differential gears 22 and 24, each with two wheels forming inputs identified by the letters a and b respectively, a satellite c and a d-shaft, the letters being preceded by the reference of the corresponding differential gear. The a and b-shapes of the two spherical differentials 22 and 24 are each cinematically connected to one of the A, B, C and D-shapes. Each of these satellite systems is also connected to the axis of the gear on which the rotors rotate.

A third spherical differential gear 26 also includes two wheels forming inputs 26a and 26b, a satellite 26c and a shaft 26d. The wheels 26a and 26b are connected to joint pignons of the d-shafts of spherical differentials 22 and 24 respectively.B, C and D. Thus, by connecting the 26d shaft of the differential 26 to a timing gear 27 in a conventional way, it is possible to display the time corresponding to the average of the frequencies of the swings of each of the sets A, B, C and D. Since the swings are in such planes that the relative orientation of each of the swings in relation to the others is the same, regardless of the swings considered, the result is that the gait is practically not influenced by the position of the movement.

The movement 30 is a truncated pyramid with two equilateral triangular bases and three trapezoidal sides, which, in the absence of truncature, would form three isosceles rectangular triangles. This pyramid forms part of a cube with three faces formed by a square obtained by adding a second rectangular triangle adjacent to the three rectangular triangles.

Movement 30 also shows on mobiles such as a road and a crankshaft not shown in the drawing, means of displaying time formed by hands 18 as shown in Figure 2.

In order to ensure that the time shown corresponds to the average of the times measured by the three swings 16, the movement 30 is fitted with a structure of the differential type 32 (see Figure 4) which is connected kinematically to each of the barrel 12s. More specifically, as referred to in Figure 4, this structure 32 includes two spherical differential gears 34 and 36.

A second spherical differential gear 36 also comprises two wheels forming inlets 36a and 36b, a satellite 36c and a 36d shaft. The inlet 36a of differential gear 36 is kinematically connected to the 34d shaft of differential gear 34 by means of a 34th jointed gear 34d, while the inlet 36b is kinematically connected to barrel 12 of the G-set. The wheels 36a, 36b drive with the satellite 36c, which rotates the 36d shaft of the differential gear 36. The motion of the 36d shaft of the differential is therefore a combination of the motions applied to the inlets 34a and 34b of the differential 36 and 36a at the inlet of the differential 36.In this case, however, the differential gear structure is not symmetrical. It is therefore necessary to adjust the gear ratios so that, for each oscillation of the balance, the angle travelled by the display means is the same. Thus, the rotational motion of the 36d shaft of the differential 36 corresponds to the sum of the rotational motions of the 34a and 34b inputs of the 34 and 36a differentials of the 36 differential, which are functions of the frequency of the 16 swingers of the three sets E, F and G. Thus, by classical connecting the 36d shaft of the 36 differential, the 36d differential is the same as the 36a differential.The time display can be made by a 36th gear on a 37th timer gear, which is the average of the frequency of the swings of each of the sets E, F and G. In this variant, the three swings are inclined relative to the plane of motion and to the axis of the means of display.

It is obvious that differential gears 34 and 36 can also be arranged so as to be concentric, equipped with a single 36d shaft. Such a configuration is shown in Figure 5, the identical elements to the realization of Figure 4 are taken up with the same references. Wheels 34a and 34b are respectively kinematically connected to the 12th barrel of sets E and F, while wheel 36b is connected to the 12th barrel of set G. The satellite 34c is solidary of a 38th shaft mounted pivoting on the 36d shaft, the shaft 38 being solidary in rotation with the 36a wheel.

As soon as the swingers swing in different planes, it is necessary to connect the differential inputs to the barrels 12 by conical gears, well known to the professional, such as the one schematically represented in Figure 6.

In both variants described above, each swing is fed by its own barrel, and it is also possible to have only one barrel and a tree-like structure, the barrel forming the trunk, while differential structures 20 or 32 allow for the existence of four, respectively three branches, each leading to the feeding of a swing.

With such clock movements, the effect due to the changes in position is greatly reduced, but a residual effect due to the point of attachment of the spirals to the barrel may remain. To completely eliminate this defect it is possible to replace each of the swings with a tourbillon, the axes of the cage and the swing being perpendicular to the faces of a regular polyhedron.

The regular polyhedra considered are a tetrahedron and a cube. It is obvious that the effect obtained could be the same with a polyhedron with more sides. However, the complexity of the mechanism and the volume occupied would be significantly increased, for a modest improvement in precision.

Claims (6)

1. A movement for a timepiece including an energy source (12), a time base provided with several balances (16) pivoting around their respective pivot axis, linking means (14) for linking the energy source (12) to the time base, and wheels arranged to support means for displaying the time (18), characterized in that said balances (16) are oriented such that planes perpendicular to their pivot axes define a regular polyhedron.
2. The movement according to claim 1, characterized in that said time base comprises four balances (16) and in that said polyhedron is a regular tetrahedron.
3. The movement according to claim 1, characterized in that said time base comprises three balances (16) and in that said polyhedron is a cube.
4. The movement according to one of claims 1 to 3, characterized in that the energy source comprises at least one barrel (12) per balance (16), in that said barrel (12) is connected to the balance (16) by a gear train (14), and in that it further includes a differential-type structure (20, 32) linking each of the gear trains (14) to said wheels arranged to support means for displaying the time (18).
5. The movement according to one of claims 1 to 3, characterized in that it further includes a differential-type structure and in that the energy source comprises at least one barrel kinematically linked to said wheels and to the balances by said differential-type structure.
6. The movement according to one of claims 1 to 5, characterized in that the means for displaying the time (18) rotate around an axis forming non-right angles with the axis of the balances (16).