CH716400A2 - Clockwork movement with a mobile rotating peak for setting the balance-spring. - Google Patents

Abstract

The invention relates to a mechanical watch movement (2) comprising a mechanical oscillator (4) formed by a balance wheel and a hairspring, a balance bridge (10), a support (50) for the balance bridge and an escapement, and a eyebolt (9) for attaching an outer end of the hairspring to the balance bridge. The mechanical watch movement is characterized in that the peak (8) is fixed directly to the balance bridge (10), and in that the balance bridge (10) is arranged to move in rotation relative to the support (50) so as to allow a benchmarking of the mechanical oscillator. In particular, the watch movement comprises a tourbillon, said support forming a base of the tourbillon carriage, the support (50) may for example be a plate, a bridge or even the base of a tourbillon cage.

Description

Description

Technical area

The invention relates to the field of watch movements of the mechanical type and more particularly the arrangement of a peak capable of undergoing rotation for setting the benchmark of the balance-spring.

Technological background

[0002] Several mechanical movements include a stud, designed to fix the outer end of the hairspring to the balance bridge, and a stud holder arranged in rotation on the balance bridge. In general, the stud holder is formed by an annular part, arranged around a bearing associated with an anti-shock device carried by the balance bridge, and by an arm which extends radially from the annular part, the stud being arranged on the side of the free end of the arm. The outer end of the hairspring can be fixed to the stud in various ways known to those skilled in the art, in particular by means of a conical pin or by gluing.

[0003] In mechanical movements fitted with a conventional stud holder movable in rotation, the arm of the stud holder is generally arranged above the hairspring on the side opposite to the support of the balance bridge (this support being for example a plate, a bridge or the base of a tourbillon cage) and therefore on the side of the bearing associated with the anti-shock device carried by the balance bridge, so as to be accessible to the watchmaker from above, that is to say from the side opposes the spiral, so that it can carry out the positioning.

[0004] In watch movements with a balance bridge having a certain symmetry in projection in its general plane, it is often sought to arrange the radial arm of the stud carrier so that it respects this symmetry, which amounts to providing a alignment of this arm with an axial plane of symmetry of the balance bridge. The reason for this choice is primarily aesthetic, the eye being sensitive to symmetry and consequently to a lack of symmetry. However, when setting the mark, the watchmaker must adjust the angular position of the eyebolt and therefore of the radial arm of the eyebolt carrier. It resulted from this benchmarking that the arm can then present a certain angular offset relative to the axial plane of symmetry defined by the balance bridge.

Summary of the invention

[0005] The inventors have set themselves the objective of finding an alternative to conventional stud holders to solve technically the problem of an aesthetic nature mentioned above.

[0006] In addition, still for aesthetic reasons, watchmakers seek in certain constructions to limit the number of visible parts in order to have a pure design. It will be noted that this objective can also make it possible to reduce production costs by limiting the number of parts associated with the mechanical oscillator.

[0007] To this end, the present invention proposes a mechanical watch movement comprising a mechanical oscillator formed by a balance wheel and a hairspring, a balance bridge, a support for the balance bridge and the escapement associated with the mechanical oscillator, and a stud for attaching an outer end of the hairspring to the balance bridge, the balance bridge comprising:

- a central part which is centered on the axis of rotation of the balance and which has an opening in which is arranged a bearing for a pivot of the balance,

- at least one carrying part arranged on the periphery of the balance and integral with said support,

- at least one intermediate part solidly connecting the central part to said at least one peripheral supporting part respectively.

[0008] The watch movement according to the invention is remarkable in that the peak is fixed to the balance bridge and the balance bridge is movable in rotation relative to its support according to the rotation rate of the balance, so as to allow a locating the mechanical oscillator.

As the invention proposes to fix the piton directly to the pendulum, the piton holder thus becomes unnecessary so that it can be eliminated. Thanks to the rotational mobility of the balance bridge, the alignment can be carried out by varying the angular position of the balance bridge, by easily accessible means.

[0010] The peak can be fixed to an arm of the balance bridge which extends radially relative to an axis of rotation of the balance and which has a free end where the peak is arranged. The arm can make it possible to balance the balance bridge, while providing it with an interesting symmetry from an aesthetic point of view. As a variant, the peak can advantageously be fixed to an intermediate part of the balance bridge, which makes it possible to have a pure design without any protruding part on the balance bridge.

[0011] The mechanical watch movement according to the invention may also comprise a guide means for guiding in rotation at least one foot of the balance bridge or an additional ring. This makes it possible to perform a rotation of the balance bridge without varying the orientation of the rotation axis of the balance wheel.

The mechanical watch movement seien the invention may also include a means for adjusting an angular position of the balance bridge relative to the support. This allows the angular position of the balance bridge to be adjusted more precisely.

Brief description of figures

The invention will be described below in more detail with the aid of the appended drawings, given by way of non-limiting examples, in which:

- Figure 1 is a partial perspective view of a first embodiment of a mechanical watch movement according to the invention,

- Figures 2a and 2b are respectively a sectional view A-A and a top view of the mechanical clockwork movement of Figure 1,

- Figure 3 is a perspective view of a second embodiment of a mechanical watch movement according to the invention,

- Figure 4 is a partial perspective view of a third embodiment of a mechanical watch movement according to the invention,

- Figures 5a and 5b are respectively a view in section B-B and a top view of the mechanical clockwork movement of Figure 4.

Detailed description of the invention

The invention relates to a mechanical movement 2 comprising a mechanical oscillator 4 formed by a balance wheel 6 and a hairspring 8, a balance bridge 10, a support 50 for the balance bridge and for an escapement (represented in Figures 5a and 5b) associated with the mechanical oscillator, and a stud 9 for fixing an outer end of the hairspring to the balance bridge.

In Figures 1,2a and 2b, the balance bridge 10 comprises:

- a central part 12 which is centered on the axis of rotation 18 of the balance and which has an opening 14 in which is arranged a bearing 16 for a pivot of the axis of balance 20,

- at least one carrying part 22 on the periphery of the balance, this carrying part being extended by a foot 30 supporting link 50, and

- at least one intermediate part 24 solidly connecting the central part 12 to said at least one peripheral carrying part respectively.

In the practical examples shown, the watch movement comprises a tourbillon, the support 50 forming a base of the tourbillon cage. The balance bridge 10 comprises two supporting parts 22, each extended by a foot 30, 30A connected to the support 50, and two intermediate parts 24 each connecting a supporting part 22 to the central part 12 of the balance bridge.

[0017] The watch movement according to the invention is characterized in that the peak 9 is fixed to the balance bridge 10, and in that the balance bridge is mobile agency in rotation relative to the support 50 around the axis of rotation 18 of the balance wheel, so as to allow the mechanical oscillator 4 to be located.

[0018] In the examples represented in the figures, the peak 9 is fixed by a screw 9a to an additional arm 28 of the balance bridge, this additional arm which extends radially relative to the axis of rotation 18 of the balance and which has an end free where the piton is arranged. The arm is here positioned relative to the intermediate parts 24 so that the balance bridge has a plane of symmetry to seek a pleasant aesthetic effect. In a variant, the stud can advantageously be fixed to an intermediate part 24 of the balance bridge, the arm 28 then being useless as a stud holder and can therefore be omitted.

[0019] To make the balance bridge mobile relative to the support, the foot 30, respectively the feet 30A extending the bearing parts 22 can/can be either mounted (s) mobile(s) in rotation directly on the support 50 (eg 1 -2), or fixed to an additional ring 70 (Figure 3) or 70A (Figures 4-5) which is arranged between the foot(s) and the support 50 and which is mounted rotation on said support.

In the example of Figures 1-2, a ring portion, connected to the two bearing parts 22, constitutes a single foot 30 for these two bearing parts. The foot 30 is here rotatably mounted on the support 50. Alternatively, each carrier part 22 can be extended by a separate foot, as in the following figures.

In the example of Figure 3, the separate foot 30A of each carrier part 22 is fixed here by screws 31 to an additional ring 70 open and resting on an upper face 50b of the support 50 and rotatably mounted on this support. In the example of Figures 4-5, the separate foot 30A of each bearing part 22 is fixed to an additional ring 70A closed and of suitable shape to cover the support 50.

[0022] The watch movement advantageously comprises a guide means for guiding the foot 30 or the additional ring 70, 70A in rotation relative to the support 50.

In the example of Figures 1-2, the foot 30 comprises three oblong guide windows 40. Each guide window 40 is in an arc of a circle, centered on the axis of rotation 18 of the balance, and is arranged to receive a pin 52 integral with the support 50. The pins have a diameter adjusted to the width of the guide windows, so that these windows and their respective pins together form the guide means for guiding the foot in rotation relative to the support, while preventing any translation of the balance bridge along a radial axis. Note that three windows are represented in the Variant described, but it is also possible to provide two or more than three in another Variant. For precise guidance, the windows are advantageously offset relative to each other by an angle of between 60° and 180°.

In the example shown in Figure 3, the additional ring 70 includes an inner edge 82 defining three pads 84 projecting from the annular portion of the ring in the direction of rotation tax 18; each shoe has an inner side face arranged to come into contact with the outer side face 55 of a boss 54 of the support 50; the side face 55 of the boss is preferably cylindrical and centered on the axis of rotation. The pads 84 and the boss 54 together form a guide means for guiding the rotation of the balance bridge with precision relative to the support. Note that three pads 84 are represented in the example, but it is also possible to provide only two or more than three in another variant. In a variant not shown, the pads are removed and the inner edge of the additional ring is provided cylindrical and sized to come directly into contact with the outer side face 55 of the boss 54, so that the cylindrical inner edge of the ring and the face side 55 of the boss then together form the guide means.

In the example of Figures 4, 5a and 5b, the additional ring 70A comprises a lower part having a lower opening adjusted to the external dimensions of the support (here a disc-shaped base) and an upper part having an upper opening of dimensions smaller than the dimensions of the lower opening, the upper part thus defining an inner cornice 70a which abuts against an upper surface 50b of the support. The contact of the outer side face 50a of the support with the inner side face 70b of the lower part of the ring 70A forms the guide means.

Note that the three examples of guide means described above can be used both to guide the rotation of a foot 30 and an intermediate ring relative to the support 50.

[0027] A watch movement according to the invention advantageously comprises means for adjusting the angular position of the balance bridge relative to the support 50.

In both variants of Figures 3 and 4-5, the additional ring 70, 70A comprises an oblong radial opening 86 with respect to axis of rotation 18 of the balance, this radial oblong opening being arranged to cooperate with an eccentric adjustment 88 arranged inside this opening so that a rotation of this adjustment eccentric rotates the additional ring 70, 70A around the axis of rotation. The adjustment means (more precisely in this example the dimensions of the radial oblong opening and the eccentric) can be configured in such a way as to allow the adjustment of the angular position of the balance bridge 10 relative to the support 50 in a range of positions angles which extends over approximately twenty degrees (20°). It will be noted that such an adjustment means can just as well be envisaged for a watch movement not comprising an intermediate ring (as in Figures 1-2), by associating this adjustment means directly with the foot 30.

Finally, a watch movement according to the invention comprises a clamping means to immobilize the balance bridge relative to the support, after adjusting the angular position of this balance bridge during a benchmarking of the oscillator mechanics 4. In the example of Figures 1 and 2, the foot 30 comprises four oblong clamping holes 32 in an arc of a circle, centers on the axis of rotation 18 of the pendulum. The oblong clamping holes are each arranged to receive a clamping screw 34 adapted to secure the balance bridge 10 to the support 50. The particular shape of the oblong clamping holes, which extend according to an arc of a circle centered on 18, makes it possible to pivot the balance bridge relative to the support. Note that four oblong clamping holes are represented here, but it is also possible to provide less or more. In the example of Figure 3, the additional ring 70, partially open, also comprises four oblong clamping holes 72 distributed around its periphery. As in the previous example, each oblong clamping hole 72 is in an arc of a circle, centered on the axis of rotation 18 of the balance, and arranged to receive a clamping screw 74.

In the example of Figures 4-5, the additional ring 70A is associated with at least two clamping flanges 78 (in particular three flanges) arranged under this additional ring 70A and coming to rest on a lower surface of the support 50. The additional ring comprises lower recesses 76 each arranged to accommodate a clamping flange 78. Finally, the support comprises lower recesses 56 each arranged to receive a free end of a clamping flange 78. Each interior recess 56 of the support is angularly wider than the flange 78 which it accommodates, so as to allow the adjustment of the angular position of the balance bridge relative to the support in order to carry out alignment.

Claims (15)

Claims 1. Mechanical watch movement (2) comprising a mechanical oscillator (4) formed by a balance wheel (6) and a hairspring (8), a balance bridge (10), a support (50) for the balance bridge and for a escapement associated with the mechanical oscillator, and a stud (9) for fixing an outer end (8a) of the hairspring to the balance bridge (10), the balance bridge comprising: - a central part (12) which is centered on the axis of rotation (18) of the balance and which has an opening (14) in which is arranged a bearing (16) for a pivot of the axis of the balance (20), - at least one carrying part (22) arranged on the periphery of the balance and integral with said support, - at least one intermediate part (24) solidly connecting the central part (12) to said at least one peripheral bearing part, respectively; characterized in that the peak (9) is fixed to the balance bridge (10); and in that the balance bridge is arranged rotatably relative to the support (50) around the axis of rotation (18) of the balance, so as to allow the mechanical oscillator (4) to be located. 2. Mechanical watch movement according to claim 1, characterized in that the stud (9) is fixed either to an additional arm (28) of the balance bridge which extends radially relative to the axis of rotation (18) of the balance and which has a free end where the eyebolt is arranged, ie at said at least one intermediate part (24). 3. Mechanical watch movement according to claim 1 or 2, characterized in that there is provided at least one foot (30; 30A) extending said at least one carrier part (22), said at least one foot being either mounted movable in rotation directly on said support (50), or fixed to an additional ring (70; 70A) which is arranged between the foot and said support and which is rotatably mounted on this support. 4. Mechanical watch movement according to the preceding claim, characterized in that it comprises a guide means for guiding in rotation said at least one foot or the additional ring relative to said support. 5. Mechanical watch movement according to the preceding claim, characterized in that said at least one foot or the additional ring (70A) comprises a lower part having a lower opening adjusted to the lateral dimensions of said support (50), so as to thus form said guide means, and an upper part having an upper opening whose dimensions are smaller than the dimensions of the lower opening, said upper part defining a lower cornice (70a) which abuts against an upper surface (50b) of said support. 6. Mechanical watch movement according to claim 4, characterized in that said at least one foot (30) or the additional ring comprises at least two oblong guide windows (40) in an arc of a circle centered on the axis of rotation (18) of the pendulum and offset by an angle of between 60° and 180°, said guide windows each being arranged to receive a pin (52) integral with said support (50), said guide windows and the respective pins together forming said guide means . 7. Mechanical watch movement according to claim 4, characterized in that said at least one foot or the additional ring (70) comprises an inner edge (82) arranged to come into contact with an outer lateral face (55) of a boss (54) of said support (50), this outer side face being at least locally cylindrical and centered on the axis of rotation, said inner edge (82) and said outer side face (55) together forming said guide means. 8. Mechanical watch movement according to claim 7, characterized in that the inner edge (82) of said at least one foot or of the additional ring (70) defines at least one pad (84) projecting from the annular part of this ring additional in the direction of the axis of rotation (18), the inner side face of each pad being arranged to be in contact with the outer side face (55) of the boss (54), said at least one pad and the boss together forming said means guidance. 9. Mechanical watch movement according to one of the preceding claims, characterized in that it also comprises means for adjusting the angular position of the balance bridge (10) relative to said support (50). 10. Mechanical watch movement according to Claim 9 in combination with Claim 3, characterized in that the said at least one foot (30) or the additional ring (70) comprises a radial oblong opening (86) with respect to the axis of rotation ( 18) of the balance, this radial oblong opening being arranged to cooperate with an adjustment eccentric (88) so that a rotation of this eccentric in the radial oblong opening generates a precise rotation of said at least one foot or of the additional ring around said axis of rotation. 11. Mechanical watch movement according to claim 9 or 10, characterized in that said adjustment means is configured so as to allow the adjustment of the angular position of the balance bridge relative to said support in a range of angular positions which extends over about twenty degrees (20°). 12. Mechanical watch movement according to one of claims 3 to 8, characterized in that said at least one foot (30) or the additional ring (70) comprises at least one oblong hole (32; 72) in an arc of a center on rotation tax (18) of the balance and each arrangement to receive a clamping screw (34; 74) to secure the balance bridge (10) to said support (50). 13. Mechanical watch movement according to one of claims 3 to 8, characterized in that said at least one foot or the additional ring (70A) is associated with at least two clamping flanges (78) arranged under said at least one foot. or said additional ring (70A) and the free end of which bears respectively against a lower surface of said support (50). 14. Mechanical watch movement according to claim 13, characterized in that said at least one foot or said additional ring (70A) comprises at least one lower recess (76) arranged to partially house respectively said at least one clamping flange (78 ). 15. Mechanical watch movement according to claim 13 or 14, wherein said support (50) comprises at least one lower recess (56) arranged to partially receive respectively said at least one clamping flange (78), each lower recess (56 ) being angularly wider than the free part of the clamping flange which it accommodates, so as to allow adjustment of the angular position of the balance bridge relative to said support.