NL2029137B1 - An oscillator for a mechanical watch - Google Patents

Abstract

An oscillator (1) for a mechanical watch, said oscillator embodied with a frame (5) supporting vibratory masses (2, 3), wherein each vibratory mass (2, 3) connects with at least one flexural member (6, 7, 8, 9) to the frame (5), and wherein at least one further flexural member (4) provides a connection between the vibratory masses (2, 3) without said at least one further flexural member (4) connecting directly to the frame (5), and wherein the at least one further flexural member (4) comprises a single lumped flexure (4’) with flexible members (10, 11, 12, 13) on opposite sides of the single lumped flexure (4), wherein the flexible members (10, 11, 12, 13) connect to the masses (2, 3).

Description

An oscillator for a mechanical watch

The invention relates to an oscillator for a mechanical watch, said oscillator embodied with a frame supporting vibratory masses, wherein each vibratory mass connects with at least one flexural member to the frame, and wherein at least cne further flexural member provides a connection between the vibratory masses without said at least one further flexural member connecting directly to the frame, wherein said at least one further flexural member arranges that the vibratory masses have a same vibratory direction.

Such an oscillator for a mechanical watch is disclosed by

NL 2024076 in the name of the applicant.

Although the known oscillator for a mechanical watch operates quite satisfactory, the inventors have strived for further simplification, without compromising qualities such as robustness against shocks, and accuracy of the oscillator for the mechanical watch.

According to the invention an oscillator for a mechanical watch is now proposed with the features of one or more of the appended claims.

Although different embodiments according to the invention are feasible, a joint feature of all embodiments is that the at least one further flexural member is embodied with an elongate single lumped portion with flexible portions on opposite sides of the elongate single lumped portion, wherein the flexible portions connect the elongate single lumped portion to the masses. This simplifies the design of the oscillator tremendously without sacrificing its resistance against shocks, whilst at the same time maintaining accuracy. Accordingly size reductions are possible and manufacturing cost savings are achieved. By virtue of the elongate single lumped portion with flexible portions on opposite sides of the elongate single lumped portion, the elongate single lumped portion has two clearly defined rotation points on its opposite ends, which promotes the accuracy of the design.

In its simplest form the elongate single lumped portion has on each of its opposite sides a single flexible portion. This links the two masses of the oscillator so as to behave with a

- 2 = single degree of freedom.

In a more accurately operating embodiment the elongate single lumped portion has a set of two flexible portions on each of its opposite sides, wherein the flexible portions of each set diverge away from the elongate single lumped portion at a predefined angle.

It is preferred that a virtual line that connects rotation points of the flexible portions with opposite sides of the elongate single lumped portion is substantially parallel to a virtual line that connects rotation points of the masses.

Other possible beneficial features are that the oscillator is planar and made in a single piece, and that the oscillator is mirror symmetric. This supports the beauty of the mechanical watch in which the oscillator of the invention is applied.

The invention will hereinafter be further elucidated with reference to the drawing of exemplary embodiments of elements of a mechanical watch according to the invention that is not limiting as to the appended claims.

In the drawing: — figure 1 schematically shows different parts of an oscillator for a mechanical watch according to the prior art in a top view; and - figures 2 and 3 schematically show different embodiments of an oscillator for a mechanical watch according to the invention in a top view.

Wherever in the figures the same reference numerals are applied, these numerals refer to the same or similar parts.

Having deleted parts that are not essential to understanding the prior art or the invention, the figures 1-3 depict features of the oscillator for an oscillator of the prior art and according to the invention.

For a good understanding of the invention, hereinafter first a brief discussion of the prior art oscillator for a mechanical watch will be provided with reference to figure 1.

Figure 1 depicts an oscillator 1 embodied with vibratory masses 2, 3 mounted on a frame 5, wherein each of the masses 2, 3 connects to at least one flexural member 6, 7, 8, 9. Figure 1 shows the application of two masses 2, 3, but this number is arbitrary; there can be more vibratory masses.

- 3 =

The oscillator 1 usually cooperates with an escape wheel 14, for which purpose anchor teeth 15, 16 are indirectly connected with the vibratory masses 2, 3, in a way that motions of the anchor teeth 15, 16 depend on motions of the vibratory masses 2, 3. This is however not essential for the invention.

At least some of the above features discussed with reference to the prior art oscillator shown in figure 1, are also applied in the oscillator 1 of the invention as depicted in figures 2 and 3. In particular, with reference to the embodiments shown in figures 2 and 3, this relates for instance to the feature that at least one further flexural member 4 provides a connection between the vibratory masses 2, 3 without said at least one further flexural member 4 connecting directly to the frame 5. In the prior art oscillator of figure 1 such further flexural members are indicated with reference numerals 10, 11, 12 and 13.

According to the invention the at least one further flexural member 4 comprises an elongate single lumped portion 47" wherein flexible portions are provided on opposite sides of the elongate single lumped portion 4, and wherein the flexible portions connect to the masses 2, 3. This is shown in both the embodiments of figure 2 and figure 3. The elongate single lumped portion 4’ together with the flexible portions on opposite sides of the elongate single lumped portion 4’ that connect with the masses 2, 3 are instrumental for securing the desired motion of the connected masses 2, 3 with a single degree of freedom.

In the most simple embodiment shown in figure 2 the elongate single lumped portion 4 has on each of its opposite sides a single flexible portion 10, 11.

In a more preferred embodiment as shown in figure 3, the elongate single lumped portion 4’ has a set of two flexible portions 10, 12 and 11, 13 on each of its opposite sides, wherein the flexible portions 10, 12 and 11, 13 of each set diverge away from the elongate single lumped portion 4’ at a predefined angle.

In both embodiments of figure 2 and figure 3 the oscillator 1 has a single degree of freedom, however the embodiment of figure 3 provides a more accurate displacement of the masses 2, 3 in their single degree of freedom, resulting in improved timekeeping behaviour of the mechanical watch in which the oscillator 1 of the invention is applied.

A feature that applies to both the embodiment of figure 2 and the embodiment of figure 3 is that a virtual line that connects rotation points of the flexible portions 10, 11, 12, 13 with opposite sides of the elongate single lumped portion 4° is substantially parallel to a virtual line that connects rotation points of the masses.

Preferably the oscillator 1 of the invention is planar and made in a single piece.

As depicted in figure 2 and figure 3 it is further preferred that the oscillator 1 is mirror symmetric.

Although the invention has been discussed in the foregoing with reference to exemplary embodiments of the oscillator for a mechanical watch of the invention, the invention is not restricted to these particular embodiments which can be varied in many ways without departing from the invention. The discussed exemplary embodiments shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiments are merely intended to explain the wording of the appended claims without intent to limit the claims to these exemplary embodiments. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.

Aspects of the invention are itemized in the following section. 1. An oscillator (1) for a mechanical watch, said oscillator embodied with a frame (5) supporting vibratory masses {2, 3), wherein each vibratory mass (2, 3) connects with at least one flexural member (6, 7, 8, 9) to the frame (b), and wherein at least one further flexural member (4) provides a connection between the vibratory masses (2, 3) without said at least one further flexural member (4) connecting directly to the frame (5), wherein said at least one further flexural member (4) arranges that the vibratory masses (2, 3) have a same vibratory direction, characterized in that the at least one further flexural member (4) is embodied with an elongate single lumped

— 5 = portion (4') with flexible portions (10, 11, 12, 13) on opposite sides of the elongate single lumped portion (4), wherein the flexible portions (10, 11, 12, 13) connect the elongate single lumped portion (4’) to the masses (2, 3).

2. The oscillator for a mechanical watch according to claim 1, characterized in that the elongate single lumped portion (4') has on each of its opposite sides a single flexible portion (10, 11).

3. The oscillator for a mechanical watch according to claim 1, characterized in that the elongate single lumped portion (4’) has a set of two flexible portions (10, 12; 11, 13) on each of its opposite sides, wherein the flexible portions (10, 12; 11, 13) of each set diverge away from the elongate single lumped portion (4’) at a predefined angle.

4. The oscillator for a mechanical watch according to any one of claims 1-3, characterized in that a virtual line that connects rotation points of the flexible portions (10, 11, 12, 13) with opposite sides of the elongate single lumped portion (4') is substantially parallel to a virtual line that connects rotation points of the masses (2, 3).

5. The oscillator for a mechanical watch according to any one of claims 1-3, characterized in that the oscillator is planar and made in a single piece.

6. The oscillator for a mechanical watch according to any one of claims 1-4, characterized in that the oscillator is mirror symmetric.

Claims (6)

CONCLUSIONS 1. An oscillator (1) for a mechanical watch, the oscillator having a frame (5) supporting vibration masses (2, 3), each vibration mass (2, 3) having at least one bender (6, 7, 8, 9) is connected to the frame {5), and wherein at least one further bending member (4) provides a connection between the vibration masses (2, 3) without said at least one further bending member (4) connecting directly to the frame (5), wherein the at least one further bending member (4) ensures that the vibrating masses (2, 3) have the same vibration direction, characterized in that the at least one further bending member (4) is designed with an elongate, single-thickened part (4') with flexible parts (10, 11, 12, 13) on either side of the elongated single thickened part (4), the flexible parts (10, 11, 12, 13) connecting the elongated single thickened part (4') connect to ground (2, 3). An oscillator for a mechanical watch according to claim 1, characterized in that the elongated single thickened portion (4') has a single flexible portion (10, 11) on each of its opposite sides. Oscillator for a mechanical watch according to claim 1, characterized in that the elongated single thickened part (4') has on each of its opposite sides a set of two flexible parts (10, 12; 11, 13), the flexible portions (10, 12; 11, 13) of each set diverge at a predetermined angle away from the elongated single bead (47). Oscillator for a mechanical watch according to any one of claims 1 to 3, characterized in that a virtual line connecting the points of rotation of the flexible parts (10, 11, 12, 13) to opposite sides of the elongated single beaded part (4') is essentially parallel to a virtual line connecting the points of rotation of the masses (2, 3), An oscillator for a mechanical watch according to any one of claims 1 to 3, characterized in that the oscillator is flat and made in one piece. - 7 = An oscillator for a mechanical watch according to any one of claims 1 to 4, characterized in that the oscillator is mirror-symmetrical.