EP2063325B1 - Mechanical watch movement - Google Patents

Description

Technical area

The present invention relates to a mechanical watch movement, in particular the regulating member of a mechanical watch movement.

State of the art

The mechanical regulating members comprise a pendulum driven on a rotating axis and a spiral whose contractions determine the running of the watch. The inner end of the spiral is integrally connected to the axis of the balance beam through the ferrule. The outer end of the hairspring is itself integrally linked to the plate or the pendulum bridge through a peg.

This traditional arrangement, however, is detrimental to the precision and isochronism of the watch. Indeed, it is known that the center of gravity of the spiral moves as the spiral winds and unwinds around the axis; this movement produces the same effect as an imbalance of the balance and generates an undesirable fluctuation of the torque applied to the axis of the balance. To remedy this inaccuracy, the spirals often have an outer tail whose shape is calculated to maintain the center of gravity of the spiral above the axis of the spiral. As the spring is flexible, the correction does not apply in the same way on all turns of the spring whose spiral shape tends to deform. A large correction is applied on the outer turns, while the inner turns that act more directly on the axis of the balance are less affected. Consequently, the torque applied on the central axis varies and the isochronism is not perfect.

Requirement EP1605322 discloses a regulating member in which the inner end of the hairspring is connected to the axis of the balance beam through a ferrule free to move axially along this axis. This solution does not solve the problem of isochronism mentioned.

On the other hand, any shocks imparted to the movement are transmitted to the large mass of the balance through its central axis. To dampen these shocks, damping elements must be provided. For this purpose, shock absorbers are generally used such as Incablocs® systems which absorb axial shocks on the axis of the balance, while allowing rotation with less friction. These shock absorbers however increase the regulating organ and increase its complexity and difficulty of assembly.

Finally, the axis of the pendulum is generally linked to a pendulum bridge that increases the thickness of movement.

FR 2,447,571 discloses a mechanical watch movement according to the preamble of claim 1.

Brief summary of the invention

An object of the present invention is therefore to provide a regulating member which avoids these disadvantages.

According to the invention, these objectives are achieved in particular by means of a mechanical watch movement as defined in claim 1.

The use of a fixed axis makes it possible to eliminate the shock absorbers and the balance bridge. On the other hand, the disturbances of the isochronism are largely avoided, since the correction of the position of the center of gravity caused by the tail of the spiral spiral is applied near the points of attachment to the balance.

Brief description of the drawings

• la figure 1 illustre une vue en perspective depuis le dessus d'un organe réglant selon l'invention ;
• la figure 2 illustre une coupe avec perspective partielle d'un organe réglant selon l'invention ; et
• la figure 3 illustre une coupe perpendiculaire au plan du mouvement de l'organe réglant selon une autre forme d'exécution de l'invention.

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

• the figure 1 illustrates a perspective view from above of a regulating member according to the invention;
• the figure 2 illustrates a section with partial perspective of a regulating member according to the invention; and
• the figure 3 illustrates a section perpendicular to the plane of the movement of the regulating member according to another embodiment of the invention.

Example (s) of embodiment of the invention

The figure 1 illustrates a perspective view from above of a regulating member for watch movement according to the invention. The other elements of the movement are conventional and are not represented. The movement comprises a plate 2 ( figure 2 ) and a rocker 1 set in motion thanks to the energy provided by the escape wheel 9 and the escapement anchor 8. The rocker rotates about a fixed axis 7 relative to the plate 2. Elements of 72 guide integral with the balance provide lateral and axial guidance of the balance 1 on the axis 7. In the illustrated example, these guide elements comprise a socket connected to the spokes 10 of the beam and traversed by the axis 7. A stone 73 reduces friction between the rotating guide elements and the plate 2. A second stone 74 reduces friction between the guide elements 72 and the fixed axis 7, respectively the ring 70 which is fixed or driven on the axis 7. The axis 7 being fixed, shock absorbers are not necessary.

According to the illustrated embodiment, the regulating member comprises a first spiral spring 3 whose inner end is integral with the ferrule 70 and thus the fixed axis 7 of the balance 1. The end curve at the outer end 30 of the spiral is in turn related to the balance 1. In this text, the expression "end of the spiral" includes the curve end or tail at each end of the spiral, or generally the entire portion at each end of the spiral whose deformation is negligible compared to that of the entire spiral, for example the last turn at each end of the spiral.

The return torque of the hairspring is therefore applied on the periphery of the balance rather than on the central axis. In the illustrated example, the regulating member comprises a second spiral spring 5 in the same plane as the first spiral spring 3 and whose turns are deployed between the turns of the first spring. The two spirals are therefore concentric and wound in the same direction. In general, the use of a second spiral spring improves the balancing of the forces of the regulating member. Coils wound in opposite directions, in different planes, are also possible but require a greater thickness. The inner end of the second spiral 5 is also connected to the fixed axis 7, for example by means of the same ferrule 7 or an additional ferrule. In the advantageous embodiment illustrated, the inner ends of the two spirals are fixed by means of the same ferrule, but at 180 ° from each other about the axis 7. The outer end 50 of the second spiral 5 is linked to the periphery of the balance 1, preferably 180 ° of the point of attachment of the first balance to compensate for displacements of the center of gravity.

The regulating member further comprises an escapement with an anchor 8 and an escape wheel 9. The anchor 8 rotates about an axis 82 visible on the figure 2 and mounted between two stones 83, 84, one of which is connected to the plate 2. At the end of the anchor, a fork 85 that can be seen on the figure 2 collaborates with an ankle 71 connected to the guide means of the balance 1 on the axis 7, in order to limit the stroke of the anchor. The portion 81 of the anchor 8 provided with the pallets 86 is actuated by the escape wheel 9 which pivots about the axis 90 mounted between two stones, one of which is connected to the plate 2.

In the description above, the inner ends of the spirals are fixed to a fixed axis. However, it is also possible to use a rotary axis, for example the axis of the balance, and to fix the inner ends of the spirals to another point by means of a peak and a bridge.

For example, according to another embodiment illustrated in figure 3 , showing a section perpendicular to the plane of movement, the rocker 1 rotates about a rotating axis 101 between the plate 2 and a rocker bridge 102, by means of a lower pivot 103 and an upper pivot 104. The pivot upper 104 may also include a shockproof device, for example, Incabloc® type. The rocker bridge 102 comprises a pinion gate 105 fixedly secured to the rocker bridge 102 and extending below the bridge 102, towards the rotary axis 101. The pinion gate 105 comprises a pin 106 fixed at its end and on which is fixed the inner end of the first hairspring 3. The outer end 30 of the hairspring is linked to the pendulum 1.

The regulating member also comprises a second spiral spring (not shown) preferably in the same plane as the first spiral spring 3, concentric and wound in the same direction as the latter. In this case, the outer end of the second hairspring is connected to the periphery of the balance 1, preferably 180 ° from the point of attachment of the first hairspring, in order to compensate for displacements of the center of gravity. The inner end of the second hairspring may also be linked to the door 105, for example by means of the pin 106 or an additional pin.

The above description relates to a regulating member with two concentric spirals at 180 °. However, it is also possible to use three spirals out of phase by 120 °, or n spirals out of phase by 360 ° / n.

The construction is particularly advantageous for light control members, in particular regulating devices in which the hairspring, the anchor, the escape wheel and / or the balance, or any combination of these elements, are made of silicon, or light alloy.

List of elements

1

pendulum

10

Rays of the pendulum

2

Platinum

3

First spiral

30

Outer end of the first hairspring

5

Second spiral

50

Outer end of the second hairspring

7

Fixed axis of the balance

70

Ferrule

71

Ankle

72

Pendulum guide element

73

Stone between pendulum and guide element

74

Stone between fixed axis and guide element

8

Exhaust anchor

81

Anchor proper

82

Anchor axis

83

Pierre

84

Pierre

85

fork

86

pallets

9

Exhaust wheel

90

Exhaust wheel axle

91

Pierre

92

Pierre

101

Rotating axis of the balance

102

Balance bridge

103

Lower pivot

104

Upper pivot

105

Piton door

106

piton

Claims (13)

1. Mechanical watch movement, comprising a regulating member with a balance (1) and at least two concentric hairsprings (3, 5), characterized in that:

   the exterior end (30, 50) of each hairspring is integrally united with the balance (1), and

   the interior end of each hairspring is integrally united with a fixed point (7) of the movement.
2. The movement of claim 1, said fixed point (7) being constituted by a staff integrally united with the main plate (2) of the movement, wherein the movement comprises a collet (70) for fastening the interior end of said hairspring (3, 5) onto said fixed staff (7).
3. The movement of one of claims 1 or 2, wherein the balance (1) pivots around one or said fixed staff (7) integrally united with the main plate (2) of the movement.
4. The movement of claim 3, comprising guiding elements (72) for limiting the lateral and vertical play of said balance (1) relative to said fixed staff (7).
5. The movement of claim 4, comprising a pallet escapement with a pallet (81) provided with a fork and a pin (71) borne by said guiding elements (72).
6. The movement of one of the claims 1 to 5, comprising stones (73, 74) on the main plate (2) and/or on guiding elements (72) of the balance (1) in order to reduce the friction during the rotation of the balance relative to said fixed staff (7).
7. The movement of one of the claims 1 to 6, comprising only two concentric hairsprings (3, 5).
8. The movement of claim 7, the exterior end of said hairsprings (3, 5) being fastened at 180 degrees to one another on the balance.
9. The movement of one of the claims 1 to 8, wherein the interior end of said hairsprings (3, 5) being connected to a collet (70) integrally united with said fixed staff (7).
10. The movement of one of the claims 1 to 9, wherein said hairsprings (3, 5) are coplanar.
11. The movement of one of the claims 1 to 10, wherein the hairsprings (3, 5) and the balance (1) are made of silicon or of a light metal alloy.
12. The movement of claim 1, comprising a rotating balance staff (101), wherein the interior end of each hairspring is fastened by a stud (106) so that said interior end is immobile relative to the regulating member.
13. The movement of claim 12, wherein said rotating balance staff (101) turns between the main plate (2) and a balance bridge (102), the balance bridge (102) comprising a stud support (105) with the stud or studs (106) being fastened onto the stud support (105).

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