HK1239849B - Oscillator for a clock movement - Google Patents

Description

Technical field

The present invention relates to a clock movement oscillator having a shaft intended to be mounted on a clock movement structural element to define the axis of rotation of a pendulum comprising a solid hub of a suspended, angularly extended mass, bearing a first bipolar magnet, arranged at a distance from the shaft, whose magnetic poles are oriented appreciably in a tangential direction with respect to the shaft, and capable, depending on the angular position of the pendulum, of being magnetized within range of a magnetic field by at least one fixed, single-point bipolar magnet, which is a magnet of a support intended to be assembled to the clock movement structural, when the magnet is fixed on the bipolar path of the pendulum, in such a way that the magnetic forces are produced by the two poles being in a fixed position, the other magnet being fixed on the pendulum, in such a way that the magnetic force is produced by the swing of the pendulum, which is defined by the motion of the two poles, is produced by the motion of the magnet in a fixed position, which is identical to that of the pendulum, when the magnet is moved on the pendulum.

State of the art

An oscillator meeting more or less the above characteristics has already been described, by chance, in utility model DE 1789976 U, which concerns different variants of the construction of an oscillator of the electromagnetic type. The method of construction in Figure 2 concerns a pendulum comprising an arm with a free end carrying a magnet designed to cooperate with coils to maintain the oscillations of the pendulum. The arm also carries an additional magnet in its central part designed to cooperate with a fixed magnet, adjustable in position with reference to the clockwork movement, so that an adjustment of the frequency of the oscillations is made possible by changing the position of the fixed magnet with reference to the trajectory of the pendulum without the presence of a pendulum. This document could theoretically provide a way of achieving the operation of the pendulum without the presence of the pendulum and thus the possibility of maintaining the oscillations in the presence of the pendulum.

The present invention relates to oscillators with a pendulum and intended for use in a portable type of watch, such as pocket or wrist watches. The pendulum is generally combined with a spiral spring designed to produce alternating boost moments to produce the oscillating movement.

However, the manufacture of the spiral-swing oscillators is difficult to master, and in particular the production of the spiral springs requires very specific and uncommon know-how, which justifies the search for alternative solutions.

As an example, patent EP 1805565 B1 describes different oscillator design modes in which booster forces are generated by one or more permanent magnets. Specifically, this document describes the construction of an oscillator with a pendulum or anchor carrying at least one moving bipolar magnet combined with at least one fixed bipolar magnet, to generate booster forces on the pendulum or anchor intended to act on an oscillating element and in particular to reproduce the typical motion of a pendulum combined with a spiral spring, in the case of pendulum design modes.The method of cooperation of the magnetized bar with an anchor in an adjacent plane to that of the magnetized bar's movements is not clearly specified, and overall this method seems to be more of a concept than a practical functional implementation. The method of implementation in Figure 15 provides that the anchor itself carries two small permanent magnets arranged to cooperate with two fixed magnets to generate booster forces on the anchor.The design is supposed to give rise to high frequency oscillations of the anchor, which are probably difficult to achieve at a good level of isochrony.

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

A main purpose of the present invention is to propose a construction for a clock movement oscillator, as described above, without a spiral spring, which would provide good chronometric performance while presenting a simple, robust structure and not sensitive to changes in ambient temperature or shocks.

For this purpose, the present invention relates in particular to an oscillator as defined in independent claim 1.

Preferred forms of realisation are defined in the dependent claims.

The basic principle of repulsion between two magnets approaching each other, with identical polarities in relation to each other, makes it possible to generate a recall force suitable for the implementation of a clock oscillator.

The advantage is that the pendulum can be positioned in the foreground, while the fixed bipolar magnet is in a secondary plane distinct from the foreground.

In addition, the oscillator according to the present invention may have a swing bridge carrying a swing shaft pivot mounting bearing to which the fixed magnet support is attached.

In this case, the support may be attached to the swing deck in such a way that its position and/or orientation can be adjusted with reference to the swing deck.

In a preferred non-limiting embodiment, the swing may be expected to have an arranged ankle to cooperate with the anchor to maintain swing oscillations.

These features allow the oscillator of the present invention to be easily implemented in relation to an existing watch caliber without requiring major modifications.

In general, it can be expected that the first and second bipolar magnets will have an angular deviation of between 20 and 180 degrees, in which case it may be advantageous to provide that at least one of the first and second bipolar magnets is attached to the balance in such a way that it can be moved to adjust the value of the angular deviation.

The present invention also relates to a watch movement incorporating an oscillator meeting the above characteristics, as well as a watch part incorporating such a watch movement.

Brief description of the drawings

Other features and advantages of the present invention will be more clearly seen by reading the following detailed description of a preferred embodiment, made with reference to the attached drawings given as non-limiting examples, in which:Figure 1 represents a simplified perspective view of a clock movement with an oscillator according to a preferred embodiment of the invention, andFigure 2 represents a simplified and broken perspective view of the clock movement in Figure 1.

Method (s) of realization of the invention

Figure 1 shows a simplified perspective view of a clock movement with an oscillator 1 in a preferred embodiment of the present invention, while Figure 2 shows the clock movement in Figure 1 in a similar but split view to highlight some construction details.

The representation of the movement is simplified in the figures to facilitate the understanding of the characteristics of the oscillator according to the invention.

The watch movement may be an existing calibre which would be slightly modified to incorporate the oscillator according to the invention or, alternatively, it may be a new calibre specifically developed, without going beyond the scope of the invention.

The movement has a body, notably a plate 2 machined conventionally to support all or part of the movement's movements. In particular, the plate typically supports a power source, such as a spring housed in a barrel (not shown), intended to maintain the oscillations of the oscillator 1 via a finishing gear (not shown).

The oscillator 1 has a balance 4 of a generally conventional shape, i.e. it comprises a hub 6 from which at least one arm 8 extends to connect a serge 10 to the hub.

The swing 4 is solidary of a 12 shaft by which it is mounted pivoting on the clock movement mast.

A first end 14 of the shaft 12 is here pivoted into a first bearing fitted into platform 2, while the other end 16 of the shaft is pivoted into a second bearing fitted onto a swing deck 18, itself assembled to platform 2.

According to the present invention, the pendulum 4 carries at least one first bipolar magnet 20, arranged at a distance from the shaft 12. Specifically, the magnet 20 is housed here in an over-thickness-saved extension 21 on the pendulum 4's serge 10.[citation needed] The magnet 20 has a significantly tangential magnetic orientation with respect to the pendulum 4, i.e., its first and second faces 22 and 24 have opposite polarities. For example, the first face 22 may be associated with the north pole of the magnet 20 while the second face 24 may be associated with its south pole.

In addition, the swing deck 18 carries a support 26 arranged on the deck in such a way that its angular orientation in relation to the deck can be adjusted for a purpose to be explained below.

Thus, the first bipolar magnet 20 is likely, depending on the angular position of the pendulum 4, to be positioned within range of the magnetic field produced by the fixed bipolar magnet 28.

The arrangement of the support 26 on the swing deck 18 is such that the fixed bipolar magnet 28 is located on the trajectory of the first bipolar magnet 20, as defined by the pivot of the swing 4. This trajectory is essentially in the form of a portion of torus adjacent to the swing 10 of the swing 4 and located in a plane parallel to it.

In addition, the fixed bipolar magnet 28 is arranged on the support 26 in such a way that, when the first bipolar magnet 20 approaches it, identical polarities are located opposite each other to give rise to a repulsive force.

It should be noted that the extension 21 can alternatively be arranged radially on the 10th saw rather than in an axial direction, without going beyond the scope of the invention. Such an alternative reduces the load on the balance in the direction of its thickness but increases its overall diameter. The shape and dimensions of the support 26 will of course have to be adapted to the location of the extension 21 on the balance 4 and the craftsman will not have any particular difficulty in adapting these elements to his own needs.

In addition, the oscillator 1 of the present invention has a linkage device, designed to establish a kinematic link between the power source of the clock movement and the swing shaft 12, arranged in such a way that the swing is likely to exhibit a periodic oscillatory motion with maintenance.

As mentioned above, the watch movement typically has a finishing gear providing the connection between the power source and the oscillator.

Only an exhaust wheel 30, driven by the finishing gear, was shown on the figures.The exhaust wheel 30 receives continuous torque from its (invisible) gear by the energy released by the clock movement energy source, always tending to make it rotate in the same predetermined direction of rotation.

The exhaust wheel conventionally cooperates with an anchor 32 pivoted on the clockwork body. The anchor 32 typically features a fork 34 arranged to cooperate with the exhaust wheel 30 and a dart 36 arranged to cooperate with a (invisible) solidary plate wedge of the swing 4. Thus, the swing 4 periodically actuates the anchor 32 to rotate it and release the exhaust wheel 30, while the latter provides small pulses back to the anchor to maintain the swing oscillations.

Of course, other developments are possible with regard to the linking device, without going beyond the scope of the invention.

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The user can implement variations of the connection device without difficulty and without going beyond the scope of the invention.

In general, it is possible to envisage variations in the implementation of oscillator 1.

Thus, for example, it is possible to predict that the balance beam 4 carries a second bipolar magnet 40 lodged in a second extension 41 similar to the extension 21. The second magnet 40 then has the same orientation as the first magnet 20 in such a way that the magnets 20 and 40 cooperate alternately with the fixed bipolar magnet 28 to give rise, each in turn, to a repulsive force that allows the rotation direction of the balance to be reversed.

Preferably, an angular deviation of the order of 20 to 180 degrees can be provided, so that the amplitude of oscillations of the balance 4 is significantly between 180 and 340 degrees.

Furthermore, it is apparent from the figures that the balance 4 here comprises a single arm 8 having a large angular extent to ensure balance of the balance from the point of view of the masses, in particular to balance the mass of the extensions 21 and 41.

As regards the support 26, it may have a base 50, with a hole 52 to ensure its assembly to deck 18, from which the first and second arms 54, 56 extend to be positioned with an angular orientation adapted to the balance 4 itself angular to anchor 32 (in any case the platform is positioned to exhibit significantly symmetrical oscillations in relation to the straight line passing through the balance shaft and the axis of rotation of the anchor).

The first arm 54 allows the support 26 to be easily held to change its angular orientation on deck 18, similar to conventional exhaust rackets.

The second arm 56 has a housing for the fixed bipolar magnet 28, arranged here perpendicular to the main direction of the second arm 56 in such a way that the fixed magnet 28 is finally oriented tangentially with reference to the belt 10 of the pendulum 4.

These characteristics and the possibility of adjusting the orientation of the support 26 not only allow the fixed magnet 28 to be positioned precisely on the trajectory of the magnets carried by the balance, but also allow a mechanical stop to be defined to provide safety against the balance being blown in the event of an impact.

It should be noted that the bipolar magnets used for the implementation of the present invention can be made from commercially available standard magnets and the tradesman will not have any particular difficulty in choosing magnets suitable for his needs.

It should also be noted that the design of the oscillator according to the invention simplifies the design of the oscillator with reference to known solutions and also makes the oscillator less sensitive to variations in ambient temperature.

The above description is intended to describe a particular method of manufacture by way of illustration and is not limited to the implementation of certain particular features described above, such as the shapes illustrated and described for the balance or the different supports described in relation to the different magnets. It should also be noted that the professional can also adapt this instruction to make a connection device between the balance and the power source of the clock movement to meet his own needs without leaving the scope of the invention.

Generally speaking, the professional will have no particular difficulty in adapting the contents of this disclosure to his own needs and implementing a clock oscillator with a pendulum bearing at least one first magnet combined with a fixed magnet arranged along the path of the pendulum bearing magnet to generate a repulsion acting as a booster force during the rotation of the pendulum, without going beyond the scope of the present invention.

Claims (9)

1. Oscillator (1) for a timepiece movement, comprising a balance (4), at least one fixed bipolar magnet (28), a support (26), and a shaft (12) that is designed to be mounted on a frame element (2) of the timepiece movement so as to define the axis of rotation of said balance (4), said balance (4) comprising a hub that is as one with a suspended mass which has an angular extent and which bears a first bipolar magnet (20) that is arranged at a distance from said shaft (12), the magnetic poles of this magnet being oriented essentially along a direction that is tangential to said shaft, it being possible for this magnet, depending on the angular position of said balance (4), to be brought within range of a magnetic field produced by the at least one fixed bipolar magnet (28) which is as one with the support (26) that is designed to be joined to the frame (2) of the timepiece movement, said at least one fixed bipolar magnet (28) being arranged on said support (26) in such a way that, when said first bipolar magnet (20) moves close to said at least one fixed bipolar magnet (28), like poles are positioned facing one another so as to give rise to a return force moment acting on said balance, said suspended mass of said balance (4) bearing a second bipolar magnet (40) whose arrangement is similar to that of said first bipolar magnet (20), in such a way that said first and second bipolar magnet (20, 40) are able to alternately cooperate with said fixed bipolar magnet (28) so as to give rise to opposite respective return force moments, the oscillator comprising an anchor (32) and an escapement wheel (30) that are designed to establish a kinematic connection between a source of energy of the timepiece movement and said balance (4), and are arranged in such a way that said balance (4) can have a maintained periodic oscillating movement of amplitude greater than 90 degrees, and can periodically actuate said anchor (32), characterized in that said at least one fixed bipolar magnet (28) is positioned on the trajectory of said first bipolar magnet (20), such as this is defined by the pivoting of said balance (4).
2. Oscillator (1) according to Claim 1, said balance (4) being located essentially in a first plane, characterized in that said fixed bipolar magnet (28) is located in a second plane that is distinct from said first plane.
3. Oscillator (1) according to Claim 1 or 2, characterized in that it comprises a balance bridge (18) which bears a bearing for mounting said shaft (12) such that the latter is able to pivot, and to which said support (26) is joined.
4. Oscillator (1) according to Claim 3, characterized in that said support (26) is joined to said balance bridge (18) in such a way that its position and/or its orientation can be adjusted relative to said balance bridge (18).
5. Oscillator (1) according to one of Claims 1 to 4, characterized in that said balance (4) bears a pin that is arranged so as to cooperate with said anchor (32) in order to maintain the oscillations of said balance (4).
6. Oscillator (1) according to one of the preceding claims, characterized in that said first and second bipolar magnets (20, 40) have between them an angular spacing of between 20 and 180 degrees.
7. Oscillator (1) according to Claim 6, characterized in that at least one of said first and second bipolar magnets (20, 40) is joined to said balance (4) in such a way that it can be moved in order to adjust the value of said angular spacing.
8. Timepiece movement comprising an oscillator (1) according to one of the preceding claims.
9. Timepiece comprising a timepiece movement according to Claim 8.