EP3158402B1 - Timepiece wheel - Google Patents

Description

Field of the invention

The invention relates to a watch mobile phone in several parts, wherein said mobile comprises a first component consisting of a shaft which comprises, around a first axis of pivoting, a housing arranged for receiving a second component consisting of a board in a single axial position. The invention further relates to a watch movement comprising at least one such mobile.

The invention relates to the field of watch mechanisms, and more particularly the wheels.

Background of the invention

Many mechanical watch movements comprise at least one friction mobile, in particular to allow adjustments when the watch operates.

For example, a mechanical movement, equipped with a medium wheel, usually has a friction at the level of the clockwork.
Friction makes it possible to turn the road, independently of the finishing gear, during the time setting. Friction also allows rotation of the drive wheel plate when the watch is running.

The document FR 1222456 in the name of EBAUCHESFABRIK ETA AG describes a mobile with a board comprising three elastic arms, substantially radial, arranged to frictionally tighten a smooth shaft. More particularly, the ends of these arms have a hollow profile corresponding to the radius of the shaft.

The document US 2006/187768 in the name of MARAZUMI TAKUYA describes a wheel structure comprising a board elastically fixed on a shaft.

The document JP S59 135385 in the name of SEIKO describes a plastic wheel fixed elastically on a metal gear.

The document JP S50 91562 in the name of SEIKO describes a wheel with a board with spokes elastically fixed on a tree.

Summary of the invention

To this end, the invention relates to a multi-part watchmaker according to claim 1. Preferred embodiments are defined in the dependent claims. The invention also relates to a watch movement comprising at least one such mobile, characterized in that the composition of said mobile is restricted to said shaft and said board assembled one on the other.

Brief description of the drawings

• la figure 1 représente, de façon schématisée et en perspective, un mobile selon l'invention, comportant une planche montée à friction sur un arbre ;
• la figure 2 représente, de façon schématisée, le mobile de la figure 1, en coupe passant par l'axe de pivotement ;
• la figure 3 représente, de façon schématisée, le mobile de la figure 1, en vue de dessus ;
• la figure 4 représente, de façon schématisée et en perspective, l'arbre que comporte le mobile de la figure 1 ;
• la figure 5 représente, de façon schématisée, l'arbre de la figure 4, en coupe passant par son axe de pivotement ;
• la figure 6 est un détail de la zone d'assemblage de la figure 2 ;
• la figure 7 représente, de façon schématisée et en vue de dessus la planche que comporte le mobile de la figure 1, dans une réalisation n'ayant que deux points de contact et qui ne fait pas partie de l'invention ;
• la figure 8 est une vue de côté de la planche de la figure 7 ;
• la figure 9 est un détail en vue de dessus d'une zone centrale de la planche de la figure 7 ;
• la figure 10 représente un mode de réalisation de l'invention.
• la figure 11 représente, de façon similaire à la figure 10, une autre réalisation de l'invention, et selon laquelle il y a quatre points de contact, qui sont disposés angulairement sensiblement à 90° les uns des autres ;
• la figure 12 est une vue de côté du mobile de la figure 11, et
• la figure 13 est une coupe partielle du mobile de la figure 11, dans un plan passant par son axe de pivotement, selon un profil différent de celui de la figure 6 .

Other features and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings, in which:

• the figure 1 schematically shows in perspective a mobile according to the invention, comprising a board frictionally mounted on a shaft;
• the figure 2 represents, schematically, the motive of the figure 1 in section passing through the pivot axis;
• the figure 3 represents, schematically, the motive of the figure 1 , in top view;
• the figure 4 represents, schematically and in perspective, the tree that includes the mobile of the figure 1 ;
• the figure 5 represents, schematically, the tree of the figure 4 in section passing through its pivot axis;
• the figure 6 is a detail of the assembly area of the figure 2 ;
• the figure 7 represents, schematically and in a view from above, the board that includes the mobile of the figure 1 in an embodiment having only two points of contact and which does not form part of the invention;
• the figure 8 is a side view of the board of the figure 7 ;
• the figure 9 is a detail in top view of a central area of the board of the figure 7 ;
• the figure 10 represents an embodiment of the invention.
• the figure 11 represents, similarly to the figure 10 another embodiment of the invention, and according to which there are four points of contact, which are arranged angularly substantially at 90 ° from each other;
• the figure 12 is a side view of the mobile of the figure 11 , and
• the figure 13 is a partial section of the mobile of the figure 11 , in a plane passing through its pivot axis, in a profile different from that of the figure 6 .

Detailed Description of the Preferred Embodiments

The invention relates to a multi-part watch mobile 100.

More particularly, this mobile has friction means, and is called "friction mobile".

According to the invention, the mobile 100 comprises a first component constituted by a shaft 1. This shaft 1 comprises, around a first pivot axis D1, a housing 6 arranged for receiving a second component. This second component consists of a board 2 in a single axial position.

The board 2 has a peripheral surface 20 with reference to a second pivot axis D2.

The shaft 1 comprises, on either side of the at least one housing 6, in the direction of the first axis of pivoting D1, an axial abutment bearing surface 7 which is arranged to maintain abutment abutment board 2 on the tree 1.

This board 2 comprises at least one first elastic arm 4 radially relative to the second pivot axis D2, and a second arm 5 rigid or elastically radially relative to the second pivot axis D2.

These first elastic arms 4 and second arms 5 together form a clamp 3, which is arranged to clamp a radial bearing surface 9 that includes the shaft 1 in the vicinity of the axial abutment bearing surface 7. The friction is thus assured between the board 2 and the tree 1.

For the assembly of the board 2 on the shaft 1, the elasticity of the arms 4, 5, of the board 2, is used to allow proper positioning, and preferably a snap in position.

According to the invention, the shaft 1 comprises an introduction ramp 8, which is arranged to radially push each first elastic arm 4, and each second elastic arm 5 when the board 2 comprises, to allow the introduction of the board 2 on the tree 1.

In a particular embodiment, the board 2 comprises a first elastic arm 4 and a second elastic arm 5, symmetrical to each other with respect to the second pivot axis D2.

Advantageously, in the free state, the clamp 3 is circumscribed to a cylinder whose radius is smaller than that of a cylinder circumscribed to the radial bearing surface 9.

The central part of the board 2 comprises as many curved surfaces, in particular substantially cylindrical surfaces, as of arms 4, 5. In the variants illustrated by the figures, which comprise a first elastic arm 4, and a second arm 5, the center of the board is defined by two curved surfaces, which come to pinch the tree 1.

The figure 7 illustrates a realization of the type "two points" which is not part of the invention and where the board 2 carries on the shaft 1 in two symmetrical points P1 and P2 with respect to the axis D1. Each first arm 4 or second arm 5 thus has such a curved surface, constituted by a substantially cylindrical sector, in particular of elliptical hollow section 34, 35, whose axis C is eccentric with respect to the second pivot axis D2.

Preferably, the axis C is then further away from the substantially hollow cylindrical sector 34, 35, than the second pivot axis D2, by a value eccentricity E, visible on the figure 9 , which is between 0.1 and 0.2 times the radius of the substantially hollow cylindrical sector 34, 35, considered.

For a clockwork friction, the value of the friction is advantageously defined by a precise interval, from 0.060 to 0.080 N.cm, in order to fulfill the criteria of quality to the impact behavior, and of setting the time. It can be understood that the friction can be achieved either at surfaces of a certain magnitude, such as the substantially cylindrical sectors 34, 35, or at point areas, for example in the form of a two-point friction or four points.

A realization of the "four points" type according to the invention is visible in figure 10 : The board 2 is on the shaft 1 at four points P11, P12, P13, P14, symmetrical two by two with respect to the axis D1. The inside board radius Rp is then less than the road radius Rch at the level of the shaft 1. The four points are called P21, P22, P23, P24 for the variant of the figure 11 .

In a particular variant, the board 2 comprises first drive means 21 at the first elastic arm 4, and second drive means 22 at said second elastic arm 5 when the board 2 comprises. And these first 21 and second 22 drive means comprise raised profiled sector relief and / or reentrant, which are arranged to cooperate with complementary profile tooling for the opening of the clamp 3 during the introduction of the board 2 on the tree 1.

More particularly, the first 21 and second 22 drive means are symmetrical with respect to the second pivot axis D2.

Alternatively, the board 2 may further comprise, in the vicinity of its periphery and in its inner part, third 23 and fourth 24 drive means.

Advantageously, the board 2 comprises holding means, such as posts or bores, or the like, in its most rigid part, which are arranged to cooperate with a traction tool.

In a particular variant, the board 2 has on its lower face 21 and / or upper 22, a surface roughness greater than 6.3 micrometers Ra, for its cooperation in friction with a holding tool and / or traction.

In a non-limiting variant, the peripheral surface 20 is a toothing oriented on the second pivot axis D2.

In another variant, the peripheral surface 20 is a cam in reference to the second pivot axis D2 and to an angular reference constituted by the first arm 4 or by the second arm 5. According to the invention, the radial bearing surface 9 and the introduction ramp 8 of the shaft 1 together define a bead 10, which is arranged to immobilize the board 2 on the shaft 1 when the board is in bearing abutment on the axial abutment bearing surface 7 of the shaft 1. In particular, the radial bearing surface 9 is flush with respect to the bead 10. This draft angle makes it possible to maintain the board 2 constant height, and constant radius of friction.

The illustrated achievement Figures 11 to 13 is a realization of the invention particularly advantageous: it is a realization at four points of contact, P21, P22, P23, P24, which are arranged angularly substantially at 90 ° from each other. The junction profile between the board and the tree, as visible on the figure 13 , is different from that of the figure 6 .

The radial bearing surface 9 of the shaft 1 is under the bead, a low angle "b" of between 2 ° and 8 °, preferably close to 5 °. The lower surface of the board 2 constitutes the abutment abutment surface 7, and bears on a radial surface 11 of the shaft orthogonal to the axis D1 thereof, on an annular surface delimited by a circle. PB interior, and a PC outer circle. Because of the elasticity of the board, and the draft, the board is held firmly in this support, it comes into contact on a surface substantially reduced to a circle, PA, at the taper of the taper 9 of the 1.The projection of the circle PA, parallel to the axis D1 of the shaft 1, on the radial bearing surface 11, is located between the inner circle PB and the outer circle PC, and may, as illustrated on FIG. figure 13 , coincide with the inner circle PB.

The maintenance thus provided is excellent, and the annular range does not require a large difference in diameter, in practice this difference between the PC diameter and the diameter PB may be less than 10% of the value of the diameter PA. It is therefore possible, very advantageously, to greatly increase the support diameter PA, compared to known embodiments of flanged mobile clamped on a shaft.

In this variant, a large volume CH lube chamber is advantageously arranged in recess of the undercut cone 9, at a much more pronounced draft angle, for example from 30 ° to 45 °, so that to maximize the volume of this chamber CH, bounded on the opposite side by the radial surface 11, the bottom (in the vicinity of the axis D1) of this chamber CH being determined by the resistance calculation of the materials of the shaft 1 according to the service constraints of mobile 100.

This puncture makes the chamber CH a lubricating reservoir remaining sealed vis-à-vis the toothing 20.

In a particular embodiment, the board 2 is made of CuBe2, of thickness close to 0.12 mm, with a toothing 20 of pitch diameter close to 4.5 mm, for receiving a shaft 1 of a nearby diameter. 1.33 mm at the bearing circle PA, and its elastic arms 4 and 5 have, according to the plane of the board, a section of 0.3 mm, with a larger gap in the free state not mounted on the shaft of approximately 1.28 mm, with a diametral clamping between 0.04 and 0.05 mm on the shaft. The hollow sectors 34, 35, of substantially elliptical section, between P21 and P22 on the one hand, and between P23 and P24 on the other hand, designed to grip the shaft 1, have, in the free state, each an eccentricity of about 0.2 mm.

In a more particular embodiment, the toothing 20 is, in a vacuum, of elliptical contour to take into account the deformation of the board 2, with a homothetic eccentration to that of the bearing surfaces P21-P22 and P23-P24. This toothing 20 is symmetrical with respect to a plane of symmetry passing through the axis.

This arrangement makes it possible to weakly apply the elasticity of the board 2 during the assembly by pinching on the shaft 1, and the deformation remains confined to the elastic domain, which makes it possible to prevent the formation of burrs. The value of the friction is tainted only by a very small dispersion.

The invention also relates to a watch movement 200 comprising at least one such mobile 100. Preferably, the composition of this mobile 100 is restricted to the shaft 1 and the board 2 assembled on one another.

Claims (12)

1. Timepiece mobile component (100) in several parts, wherein said mobile component (100) comprises a first component formed by an arbor (1) which includes, about a first pivot axis (D1), a housing (6) arranged for reception of a second component formed by a plate (2) in a single axial position, said plate (2) including a peripheral surface (20) with respect to a second pivot axis (D2), said arbor (1) comprising, on either side of said at least one housing (6), in the direction of said first pivot axis (D1), an axial abutment surface (7) arranged to maintain said plate (2) in abutment on said arbor (1), wherein said plate (2) comprises a first arm (4), resilient radially with respect to said second pivot axis (D2), and a second arm (5) that is stiff or resilient radially with respect to said second pivot axis (D2), said first resilient arm (4) and second arm (5) together forming a clamp (3) arranged to clamp a radial bearing surface (9) comprised in said arbor (1) in proximity to said axial abutment surface (7), wherein said arbor (1) comprises an entry ramp (8) arranged to push back radially said first resilient arm (4) and said second resilient arm (5) when comprised in said plate (2), to allow said plate (2) to be placed on said arbor (1), said first arm (4) and said second arm (5) including a substantially cylindrical hollow section (34; 35) whose axis (C) is off-centre with respect to said second pivot axis (D2), characterized in that said axis (C) is farther from said substantially cylindrical hollow section (34; 35) than said second pivot axis (D2), by an offset value (E) comprised between 0.1 and 0.2 times the radius of said substantially cylindrical hollow section (34; 35), in that said radial bearing surface (9) and said entry ramp (8) of said arbor (1) define together a flange (10) arranged to immobilise said plate (2) on said arbor (1) when said plate is in abutment on said axial abutment surface (7) of said arbor (1), in that said radial bearing surface (9) is undercut with respect to said flange (10), by a small angle (b) comprised between 2° and 8°, and in that said plate (2) bears on said arbor (1) at only four points (P11, P12, P13, P14; P21, P22, P23, P24), in symmetrical pairs with respect to said first pivot axis (D1), in that said plate (2) includes a lower surface which forms an axial abutment surface (7) and rests on a radial surface (11) of said arbor (1) orthogonal to the axis (D1) of said arbor (1), on an annular surface delimited by an inner circle (PB) and an outer circle (PC), said plate (2) being, in an assembled position on said arbor (1), in contact with said arbor (1) on a surface substantially reduced to a circle (PA), on said radial bearing surface (9), the projection of said circle (PA), parallel to said axis (D1) of said arbor (1), onto said radial bearing surface (11), being located between said inner circle (PB) and said outer circle (PC), and coincides with said inner circle (PB).
2. Mobile component (100) according to claim 1, characterized in that said plate (2) includes two symmetrical surfaces with respect to said first pivot axis (D1) which include an inner plate radius (Rp) that is smaller than a cannon-pinion radius (Rch) comprised in two shoulders of said arbor (1) that are symmetrical with respect to said first pivot axis (D1) and opposite to said two surfaces of said plate (2).
3. Mobile component (100) according to claim 1 or 2, characterized in that, in the free state, said clamp (3) is circumscribed to a cylinder of smaller radius than that of a cylinder circumscribed to said radial bearing surface (9).
4. Mobile component (100) according to any of claims 1 to 3, characterized in that said plate (2) includes first drive means (21) on said first resilient arm (4), and second drive means (22) on each said second resilient arm (5), when said plate (2) comprises a second resilient arm, and in that said first (21) and second (22) drive means include sectors with a raised and/or recessed relief profile arranged to cooperate with a tool of complementary profile to open said clamp (3) when said plate (2) is placed on said arbor (1).
5. Mobile component (100) according to claim 4, characterized in that said first (21) and second (22) drive means are symmetrical with respect to said second pivot axis (D2).
6. Mobile component (100) according to claim 5, characterized in that said plate (2) comprises holding means, in its stiffest portion, to cooperate with a pulling tool.
7. Mobile component (100) according any of claims 1 to 6, characterized in that said plate (2) comprises, in proximity to its periphery and in its inner portion, third (23) and fourth (24) drive means.
8. Mobile component (100) according any of claims 1 to 7, characterized in that said plate (2) comprises on its lower face (21) and/or upper face (22), a state of surface roughness greater than 6.3 micrometres Ra for frictional cooperation with a holding and/or pulling tool.
9. Mobile component (100) according any of claims 1 to 8, characterized in that said peripheral surface (20) is a toothing centred on said second pivot axis (D2).
10. Mobile component (100) according any of claims 1 to 9, characterized in that said peripheral surface (20) is a cam with reference to said second pivot axis (D2) and to an angular reference formed by said first arm (4) or by said second arm (5).
11. Mobile component (100) according any of claims 1 to 10, characterized in that said four points (P11, P12, P13, P14; P21, P22, P23, P24) are disposed at angles of substantially 90° with respect to each other.
12. Timepiece movement (200) comprising at least one mobile component (100) according any of claims 1 to 11, characterized in that the composition of said mobile component (100) is limited to said arbor (1) and to said plate (2) assembled one on top of the other.

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