BALANCE WITH INERTIA ADJUSTMENT

Abstract

A balance for a horological movement includes rigid portions consisting of a hub defining the pivot axis of the balance, a felloe, four arms connecting the felloe to the hub, and including four slots for receiving and gripping in position an inertia-block, each slot being delimited by an arm and by an elastic arm including a first end integral with the arm, and a second distal end free in relation to the hub, to the arm, and to the felloe sector. The balance includes two pairs of inertia-blocks, each pair of inertia-blocks having different masses to ensure different adjusting powers, a first pair of inertia-blocks for a basic adjustment, and second pair of inertia-blocks for a precise adjustment.

Claims

1-10. (canceled)

11. A balance for a horological movement, comprising: rigid portions including a hub defining the pivot axis of said balance, a felloe, four arms connecting said felloe to the hub, and including four slots to receive and grip in position an inertia-block, each slot being delimited by an arm and by an elastic arm including a first end integral with said arm, and a second distal end free in relation to said hub, to said arm, and in relation to the felloe; and two pairs of inertia-blocks, each pair of inertia-blocks having different masses to ensure different adjusting powers, the two pairs of inertia-blocks including a first pair of inertia-blocks for a basic adjustment and a second pair of inertia-blocks for a precise adjustment.

12. The balance according to claim 11, wherein the inertia-blocks of each of the two pairs are disposed in the slots opposite in relation to the pivot axis of the balance.

13. The balance according to claim 11, wherein each pair of inertia-blocks has different dimensions, the inertia-blocks of the first pair being larger than the inertia-blocks of the second pair, or the inertia-blocks of the second pair being larger than the inertia-blocks of the first pair.

14. The balance according to claim 11, wherein the inertia-blocks of the first pair are heavier than the inertia-blocks of the second pair, or the inertia-blocks of the second pair are heavier than the inertia-blocks of the first pair.

15. The balance according to claim 11, wherein the inertia-blocks of the first pair are made from a different material that the inertia-blocks of the second pair.

16. The balance according to claim 11, wherein the inertia-blocks of the first pair and the inertia-blocks of the second pair are disposed on a distinct radius of the balance.

17. The balance according to claim 16, wherein the inertia-blocks of the first pair are disposed on a first radius closer to the felloe than the hub and the inertia-blocks of the second pair are disposed on a second radius closer to the hub of the balance than the felloe.

18. The balance according to claim 11, wherein the arms, the felloe, and the hub form a one-piece element.

19. A horological movement comprising: the balance according to claim 11.

20. The timepiece comprising: the horological movement according to claim 19.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0021] Other features and advantages of the invention will become more apparent upon reading the following description of a particular embodiment of the invention, given by way of simple illustrative and non-limiting example, and the appended FIGURE, wherein:

[0022] FIG. 1 is a perspective view of a balance in accordance with the invention according to a first embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The balance 1 for horological movement, equipped with a device for adjusting its inertia making it possible to adjust the oscillation frequency of said balance, comprises rigid portions consisting of a hub 2 defining the pivot axis A of the balance 1, a circular-shaped felloe 3, four arms 4 connecting said felloe 3 to the hub 2, and including four slots 7 for receiving and gripping in position an inertia-block 6,6′.

[0024] Each slot 7 is delimited on the one hand by an arm 4, and on the other hand by an elastic arm 5 including a first end 5B integral with said arm 4, and a second distal end 5A free in relation to said hub 2, to said arms 4, and to said felloe sector 3.

[0025] As illustrated, the balance 1 comprises four arms, forming a hub 4 at their intersection, the hub 4 being equipped with an orifice 40 intended to receive a balance arbor.

[0026] The slot 7 is delimited by a rigid portion of the arm 4 and by an elastic arm 5 that continuously returns towards the arm 4 when the inertia-block is inserted into the slot 7.

[0027] According to the invention, the balance comprises two pairs of inertia-blocks 6, 6′, each pair of inertia-blocks having different dimensions to ensure different adjusting powers, a first pair of inertia-blocks 6 for a basic adjustment, and second pair of inertia-blocks 6′ for a precise adjustment.

[0028] The inertia-blocks 6, 6′ of each pair are disposed in slots 7 opposite in relation to the pivot axis A of the balance, or also disposed according to an axial symmetry of axis A, for a balanced distribution of the masses on the balance 1.

[0029] So as to distinguish the inertia-blocks 6, 6′ and position them correctly, the inertia-blocks 6 of the first pair are larger than the inertia-blocks 6′ of the second pair, or vice versa.

[0030] According to one embodiment of the invention, the inertia-blocks 6 of the first pair and the inertia-blocks 6′ of the second pair are disposed on a distinct radius of the balance.

[0031] For example, the inertia-blocks 6 of the first pair are disposed on a first radius close to the felloe 3 and the inertia-blocks 6′ of the second pair are disposed on a second radius close to the hub 2 of the balance, the pair of inertia-blocks 6′ close to the hub 2 of the balance for a precise adjustment.

[0032] Similarly, the inertia-blocks 6 of the first pair are heavier than the inertia-blocks 6′ of the second pair, or vice versa. For this, various materials may be used to produce the inertia-blocks 6,6′. For example, the inertia-blocks 6 are made from gold or gold alloy such as 18K 3N gold, and the inertia-blocks 6′ are made from titanium or titanium alloy such as grade 5 titanium.

[0033] The inertia-blocks 6,6′ comprise a head 61 in the form of a disc and optionally a cylinder-shaped foot 62.

[0034] Advantageously, the slot 7 has a shape complementary to that of the head 61 or of the foot 62 of the inertia-block 6, 6′. This embodiment is particularly advantageous because it makes it possible to limit the thickness of the balance 1 once the inertia-blocks 6,6′ have been mounted on the balance 1.

[0035] During the installation of the inertia-blocks 6,6′ into the slots 7, the inertia-blocks 6,6′ are gripped in the slots 7 and are held by friction in their position under the effect of the elasticity of the elastic arm 5.

[0036] The adjustment inertia-blocks 6,6′ are equipped with a slot 63 to adjust the angular position of the inertia-block by means of a tool cooperating with the slot 63 to transmit a torque about the axis of rotation of the inertia-block 6,6′. According to the embodiment illustrated in FIG. 1, each inertia-block 6,6′ has an uneven part 64 on the disc forming the head 61.

[0037] Obviously, the person skilled in the art will know how to adapt the balance 1 and install any other type of inertia-block 6,6′ so as to be able to adjust the inertia of the balance 1.

[0038] Such a configuration therefore makes a simple and quick adjustment of the balance possible, the larger and/or heavier inertia-blocks firstly making it possible to perform a basic adjustment, and the smaller and/or lighter inertia-blocks secondly making it possible to refine the adjustment.

[0039] The invention also relates to a horological movement and a timepiece equipped with a balance in accordance with the invention.

[0040] Thanks to these various aspects of the invention, we have a compact balance for adjusting the position of inertia-blocks that is easy and inexpensive to manufacture.

[0041] Of course, the present invention is not limited to the example illustrated and is susceptible to various variants and modifications that will become apparent to the person skilled in the art.