CH714000A1 - Watchmaking assembly comprising a watch component fixed on an axis. - Google Patents

Abstract

The invention relates to a watch assembly (1) comprising a watch component (3) fixed on an axis (5) extending in an axial direction (Z), said component (3) comprising a receiving zone (9) delimited by at least one positioning surface and at least two holding surfaces (13), the at least one of which is displaceable against a restoring force and arranged to clamp said axis (5) against said positioning surface. According to the invention, said axis (5) comprises a section (7) of non-circular cross section, said section (7) and said receiving zone (9) being shaped so as to allow insertion of the axis ( 5) in said axial direction when said axis and said component have a first relative angular orientation as well as to clamp said section (7) against said positioning surface when said component (3) and said axis (5) have a second angular orientation relative to said first orientation.

Description

Description

Technical Field [0001] The present invention relates to the field of watchmaking. It relates, more particularly, to a timepiece assembly comprising a timepiece component fixed on an axis.

STATE OF THE ART [0002] In the field of watchmaking, it is often desired to integrate in rotation a component with an axis so as to be able to mount the component in pivoting movement. Typically, this integration is carried out by driving the axis through a hole in the component. This driving deforms the material of the component elastically, and the stresses thus generated serve to tighten the axis. The two elements are thus made integral with one another. During hunting, the material of the component typically undergoes a slight additional plastic deformation.

This fixing method is perfectly suitable for metal or polymer components which are relatively elastic and can undergo plastic deformations without breaking.

More recently, brittle materials have become common in watchmaking. These materials have little or no plastic area and are therefore extremely fragile. As such, there may be cited hard steels, ceramics, glasses, vitroceramics, mono- or polycrystalline silicon, amorphous silicon, nitride oxides or silicon carbides under any crystalline regime, alumina, synthetic diamond and the like.

Since these materials are brittle, it is very difficult, if not impossible, to drive out a component made of such a material on an axis in the traditional manner, while keeping acceptable manufacturing tolerances.

For these reasons, watch manufacturers have developed several solutions for mounting components made of such materials on axes. One of these solutions is to provide elastic structures at the level of the component mounting area, these elastic structures allowing hunting without development of excessive stresses in the material of the component. These structures are typically formed in the body of the component and flex when the axle is introduced.

As such, mention may be made of document EP 2 112 565 which describes a micromechanical part whose opening intended for its attachment to an axis comprises rigid zones alternating with elastic zones. The rigid zones ensure the correct positioning of the component on the axis and the elastic zones provide the clamping force in order to secure the two elements relative to each other.

Another interesting document is WO 2011/116 486 which describes a split ferrule comprising two elastic tongues which constrain and position the axis against a substantially rigid positioning surface when the axis is driven into the reception zone defined by languages and positioning surface.

Yet another interesting document is document EP 3 037 896. This document describes a removable piton holder which clamps a piton by the use of a non-circular key which acts on a flexible tongue. Depending on the angular position of this key, the tongue clamps the eyelet against a positioning surface or releases it. This arrangement does not lend itself well to components other than a stud and requires the additional key to lock the stud. This arrangement is thus monovalent and relatively complex.

The object of the invention is therefore to provide a timepiece component in which the above-mentioned defects are at least partially overcome.

Disclosure of the invention [0011] More precisely, the invention relates to a timepiece assembly as defined by claim 1.

This set includes a timepiece component such as a wheel, an anchor, a hairspring, a plate or the like, fixed on an axis which extends in an axial direction. Said component comprises a reception zone delimited by at least one positioning surface as well as at least two holding surfaces, at least one of which is displaceable against a restoring force in order to clamp said section against said positioning surface . These holding surfaces can be, for example, formed by fingers, tongues or the like.

According to the invention, the axis comprises a non-circular cross-sectional section (that is to say has a shape other than circular considered in a plane making a non-zero angle, in particular perpendicular, to said direction axial), this section and said receiving zone (in particular the positioning surface as well as the retaining surfaces) being shaped so as to allow the insertion of the axis substantially without driving in said axial direction when the axis and the component are mutually oriented in a first relative angular orientation, and in clamping said axis against said positioning surface when they have a second relative angular orientation, distinct from said first.

The component can thus be secured to the axis by rotary clipping instead of hunting. Conventional hunting involves significant friction between the component and the axis during this operation, which is accompanied

CH 714 000 A1 of a risk of wear of the component and / or the axle. By cons, a clipping by rotation as defined above involves less friction, and therefore reduced wear.

Furthermore, since the section of the axis is non-circular, the angular alignment of the axis and of the component can be substantially perfect and therefore does not require any manual adjustment on the part of a watchmaker.

Advantageously, said retaining surfaces are each carried by a corresponding arm, at least one of which is elastic.

Advantageously, said elastic arms partially surround said axis and are preferably folded inwards. The arms can thus act as a shock absorber to absorb shocks in certain directions.

Advantageously, said positioning surface is carried by an element which is substantially rigid and thus provides a stable reference for the positioning of the component relative to the axis.

Advantageously, said section comprises at least one flat intended to cooperate with one of said surfaces, preferably with said positioning surface. Indexing of the axis relative to the component is thus ensured without requiring manual adjustment by a watchmaker. Consequently, the indexing of a balance plate with a spiral spring, for example, can be ensured in this way.

Advantageously, said section has a height parallel to said axial direction which is between 100% and 120%, preferably between 101% and 115%, of the thickness of said component considered in the same direction. If the section is machined in a cylindrical portion of the axis, the edges of the section can act as shoulders to position the component along the axis.

Advantageously, the axis carries a locking element arranged to pass through said receiving zone when the axis and the component are oriented according to said first relative angular orientation and to lock said component axially on said axis when the axis and the component are oriented according to said second relative angular orientation. The axial locking of the component on the axis is thus ensured, regardless of the shape and the length of the section. This locking element advantageously has at least one lug arranged to lock said component axially on said axis when the axis and the component are oriented in said second relative angular orientation. A substantially polygonal shape whose vertices constitute said lugs is particularly suitable for this function.

Advantageously, said component is a spiral spring (the reception area of which is defined by its ferrule or by its piton holder), a balance, a wheel, an anchor, or a balance plate.

This set can be, of course, incorporated into a watch movement, which can in turn be integrated into a timepiece.

The invention also relates to a method of fixing a timepiece component on an axis to form a timepiece assembly. This process includes the steps of:

- providing a timepiece component comprising a reception zone delimited by at least one positioning surface as well as at least two retaining surfaces which can be moved against a restoring force and which are arranged to clamp said axis against said positioning surface;

- Provide an axis extending in an axial direction and comprising a section having a non-circular cross section arranged to cooperate with said holding surfaces as well as with said positioning surface, said section and said receiving area being shaped so allowing the insertion of the axis in said axial direction when the axis and the component have a first relative angular orientation, and clamping said axis against said positioning surface when the component and said axis have a second relative angular orientation;

orienting said axis and said component according to said first relative angular orientation;

- inserting said axis into said receiving zone in a direction parallel to said axial direction;

- Pivot said axis relative to said component to put them in said second relative angular orientation.

In doing so, the component is clipped onto the section of the axis, which implies a reduction in the friction exerted between these two elements in comparison with a conventional drive out as well as reduced wear, for the reasons mentioned above. -above. Furthermore, these two elements are thus automatically indexed without requiring manual adjustment.

Brief description of the drawings [0026] Other details of the invention will appear more clearly on reading the following description, made with reference to the accompanying drawings in which:

Fig. 1 is a schematic sectional representation of a timepiece assembly according to the invention in the insertion position of the axis;

Fig. 2 is a schematic representation of the timepiece assembly of FIG. 1 in service position;

CH 714 000 A1

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8 is an isometric view of a variant of a timepiece assembly according to the invention in the axis insertion position;

is an isometric view of the clockwork assembly of FIG. 3 in service position;

is a schematic sectional representation of another variant of a timepiece assembly according to the invention in the insertion position of the axis;

is an isometric view of the clockwork assembly of FIG. 5;

is a schematic sectional representation of the variant of FIG. 5 in service position; and is an isometric view of the clockwork assembly of FIG. 7.

Embodiment of the invention [0027] Figs. 1 and 2 show a first embodiment of a timepiece assembly 1 according to the invention, seen in partial section.

This assembly includes a timepiece component 3, which is shown here as a one-piece anchor assembled to an axis 5 of which only the section which cooperates with the anchor is shown. This section is represented by a section 7 of non-circular cross section which extends along at least part of the axis. Said non-circular shape is considered in a plane substantially perpendicular to the axis 5, and is, for example, at least partially polygonal. The latter can be fixed or mobile in rotation, can be any tree or a similar structure such as for example a piton in the form of a tree.

The timepiece component 3 comprises a hollow receiving zone 9 arranged to receive and tighten the axis 5. This zone 9 is delimited on the one hand by a positioning surface 11 and on the other hand by at least two surfaces of holding 13 which are subjected to an elastic restoring force. In the variant shown, the holding surfaces 13 are carried by elastic arms 15 which extend from the body of the component 3, and the positioning surface 11 is substantially rigid (that is to say having a rigidity such that the elastic deformations in the service position do not substantially disturb the function of the component 3). In other words, the positioning surface is substantially non-movable.

The reception area 9 and the shape of the section 7 are complementary and have a relationship such that, in a first relative angular orientation of these two elements, the axis 5 can be inserted in the area 9 in an axial direction . This relationship is illustrated in fig. 1 in solid lines and shows that there is enough play so that the section 7 does not come into contact with the timepiece component 3 when it is inserted into said zone in a direction parallel to the axis 5. Alternatively, a slight contact between axis 5 and the two surfaces 11,13 may be allowed.

Subsequently, by pivoting the axis 5 relative to the components, the periphery of the section 7 abuts against the holding surfaces 13, which are moved against the restoring force provided by the elastic arms 15. The angular relationship between these components are illustrated in fig. 1 in dotted lines, in which a corner of the section 7 is in contact with the positioning surface 11 (this contact being represented here by an overlap between the axis 3 and the holding surfaces 13). In order to limit the stresses undergone by the elastic arms 15, the positioning surface 11 may include a notch 17 which allows a corner of the section 7 to enter there during rotation. The movement of the holding surfaces 13 and also the stresses generated in the arms 15, can thus be limited.

By pivoting the axis 5 even further relative to the component 3, the axis 5 adopts a stable position in a second relative angular orientation illustrated in FIG. 2, this angular orientation being distinct from the first angular orientation mentioned above. In this position, the retaining surfaces 13 have been raised by the shape of the section and the elastic arms 15 are thus constrained (solid lines; the initial position of the elastic arms 15 is illustrated in dotted lines), and tighten the section 7 against the positioning surface 11.

In the illustrated embodiment, the section has a shape comprising a flat 7a which is positioned against the positioning surface 11 (which is also flat except for the notch 17) in the service position, as well that two rounded corners 7b arranged to be in contact with the holding surfaces 13. The flat 7a is linked to the rounded corners 7b by flat surfaces.

However, it goes without saying that a large number of forms of positioning surfaces 11, holding surfaces 13 and of the section 7 fulfill the desired purpose. Therefore, the illustrated embodiment should not be considered as limiting. One could imagine, for example, that the section has angular, curved, polygonal, oval, irregular shapes and any combination of these. The holding surfaces 13 can take the form of necklaces, fingers, tongues or any other suitable shape. As for the elastic restoring force for these surfaces, it can be provided by elastic elements of any kind which are integral with said surfaces 13 or which are constituted by additional elements brought to the component 3. Furthermore, the positioning surface can be curved, angular, irregular or any other suitable shape. Indeed, any combination

CH 714 000 A1 of shapes of the surfaces 11, 13 and of the section 7 which allow a stable tight angular position as well as an angular position which allows the axis 5 to enter the receiving zone 9, substantially without displacement of the holding surfaces 13, suitable for implementing the invention.

The axial retention of the component 3 on the axis 5 can be carried out using the edges of the section 7 as axial stops in the case where the shape of the section 5 is machined in the body of a cylindrical axis. In such a case, the section 7 does not extend all along the axis 5 but occupies a length of between 100% and 120%, preferably between 101 and 115% of the thickness of the component 3.

That said, Figs. 3 and 4 illustrate a variant in which larger axial stops are present. In this variant, component 3 is a wheel.

The axis 5 has a conventional shoulder 19, located on one side of the component. On the other side is a locking element 21, which has a triangular shape in the variant illustrated. The shoulder 19 and the locking element 21 are thus linked to each other by said section.

The locking element is shaped to enter the reception area 9 when the axis 5 is in the first angular orientation mentioned above relative to the component 3. The axis 5 can thus be inserted in the reception area 9 with play and the component 3 can be adjusted against the shoulder 19. Then, by pivoting the axis 5 relative to the component 3, the section 7 of the axis 5 is tightened as described above. In doing so, the locking element 21 is also pivoted and the pins 21a, formed by the vertices of its triangular shape, abut against the component 3 and thus prevent its removal from the axis 5 when the latter is in said second orientation. angular with respect to the component 3. The locking element 21 and the shoulder 19 thus block the component 3 axially on the axis 5. It goes without saying that other forms of locking element 21 are possible, for example forms comprising at least one lug 21a or a projecting projection arranged to form an axial stop when the axis 5 and the component 3 are in their second angular orientation.

By pivoting the axis 5 again relative to the component 3 so that they are again in their first angular orientation, the locking element can pass through the reception zone 9 and can be removed.

In the variants illustrated in FIGS. 1 to 4, the angle between the first angular orientation and the second angular orientation is 60 ° but any suitable angle can be used.

Figs. 5 to 8 illustrate another variant of a timepiece assembly 1 according to the invention. In this embodiment, the timepiece component 3 is a spiral spring of which only the ferrule and the root 3a of the spring are illustrated.

The root 3a is substantially rigid and carries the positioning surface 11. The elastic arms 15 extend symmetrically from the root 3a and partially surround the reception area 9. The latter are folded inwards in order to give them increased elasticity and defining the holding surfaces 13. The elastic arms 15 and the root 3a thus form a ferrule making it possible to attach the hairspring to the balance axis 15.

To perform this operation, the axis 5 is inserted into the zone 9 with the axis 5 and the spring 5 in a first relative angular orientation (as illustrated in solid lines in FIG. 5 as well as in FIG . 6). In this position, the locking element 21 can pass through the reception area 9. Then, the axis 5 is pivoted relative to the spring 3, for example clockwise. When these two components are in the relative angular orientation illustrated in dotted lines in FIG. 5, the section 7 abuts against the holding surfaces 13 and a corner of the shape of the section enters the notch 17. This position is also illustrated in dotted lines in FIG. 5. By pivoting the axis 5 further, the elastic arms 15 are raised and the section adopts the second relative angular orientation, which is a stable position illustrated in solid lines in FIG. 7 as well as in FIG. 8. The holding surfaces 13 of the elastic arms 15 thus tighten the section against the positioning surface 11 by means of a force provided by the elastic arms. In this position, the locking element 21 axially blocks the spring on the axis 5 as described above.

In the embodiment of FIGS. 5 to 8, the shape of the elastic arms 15 surrounding the axis 5 acts as shockproof for each direction in the plane of the component 3, except in the direction of the rigid root 3a. Indeed, in each other direction in the plane, the arms 15 can deform in response to a shock and cushion it. After this damping, the elastic arms 15 return the section 7 to its original position.

In the illustrated embodiments, the section 7 always has at least one line of symmetry but it is also possible that its shape is irregular. Furthermore, the elastic arms 15, which have been shown in symmetrical shapes, can also be different from one another and asymmetrical. Indeed, it is not important that the forces exerted by the holding surfaces are identical or are exerted symmetrically.

Even if the principle of the invention is particularly advantageous when component 2 is made of brittle material as mentioned in the preamble, it also applies to components 3 of metal or conventional polymer.

Although the invention has been particularly shown and described with reference to particular embodiments, other variants are possible without departing from the scope of the invention as defined in the claims. For example, it is possible that only one of the holding surfaces 13 is resiliently displaceable, the other being substantially

CH 714 000 A1 rigid. The skilled person is able to modify the geometry of the surfaces 11, 13, the arms 15 etc. in order to apply this possibility.

Claims (13)

claims 1. Watchmaking assembly (1) comprising a watchmaking component (3) fixed on an axis (5) extending in an axial direction (Z), said component (3) comprising a reception zone (9) delimited by at least one positioning surface (11) and at least two holding surfaces (13), at least one of which is movable against a restoring force and arranged to clamp said axis (5) against said positioning surface (11 ); characterized in that said axis (5) comprises a section (7) of non-circular cross section, said section (7) and said receiving zone (9) being shaped so as to allow the insertion of the axis (5 ) in said axial direction when said axis and said component have a first relative angular orientation as well as clamping said section (7) against said positioning surface (11) when said component (3) and said axis (5) have a second relative angular orientation distinct from said first orientation. 2. timepiece assembly (1) according to claim 1, wherein said holding surfaces (13) are each carried by a corresponding arm (15), at least one of which is elastic. 3. Clock assembly (1) according to claim 2, wherein said elastic arms (15) partially surround said axis (5). 4. timepiece assembly (1) according to claim 2, wherein at least one of said elastic arms (15) is folded inward. 5. Watch assembly (1) according to one of the preceding claims, in which said positioning surface (11) is carried by an element (3, 3a) which is substantially rigid. 6. Watch assembly (1) according to one of the preceding claims, in which said section (7) comprises at least one flat intended to cooperate with one of said surfaces (11, 13), preferably with said positioning surface ( 11). 7. timepiece assembly (1) according to the preceding claim, wherein said section (7) has a height parallel to said axial direction (Z) which is between 100% and 120%, preferably between 101% and 115%, the thickness of said component (3) considered in the same direction (Z). 8. timepiece assembly (1) according to one of claims, wherein the axis (5) carries a locking element (21) arranged to pass through said receiving area (9) when said axis (5) and said component (3) are oriented in said first relative angular orientation as well as for locking said component (3) axially on said axis (5) when said axis (5) and said component (3) are oriented in said second relative angular orientation. 9. timepiece assembly (1) according to the preceding claim, wherein said locking element (21) has at least one lug (21a) arranged to lock said component axially on said axis when the axis and the component are oriented along said second relative angular orientation. 10. Watch assembly (1) according to one of the preceding claims, in which said component (3) is chosen from a spiral spring, a balance, a wheel, an anchor, and a balance plate. 11. Watch movement comprising a watch assembly (1) according to one of claims 1 to 8. 12. Timepiece comprising a movement according to claim 11. 13. Method for fixing a timepiece component (3) to an axis (5) to form a timepiece assembly (1), comprising the steps of: - providing a timepiece component (3) comprising a reception area (9) delimited by at least one positioning surface (11) as well as at least two retaining surfaces (13) movable against a restoring force and arranged for clamping said axis (5) against said positioning surface; - Provide an axis (3) extending in an axial direction (Z) and comprising a section (7) having a non-circular section arranged to cooperate with said holding surfaces (13) as well as with said positioning surface (11 ), said section (7) and said receiving zone (9) being shaped so as to allow the insertion of the axis (5) in said axial direction (Z) when the axis (5) and the component ( 3) have a first relative angular orientation as well as clamping said section (7) of said axis (5) against said positioning surface (11) when the component (3) and said axis (5) have a second relative angular orientation; - orienting said axis (5) and said component (3) according to said first relative angular orientation; - inserting said axis (5) into said receiving zone (9) in a direction parallel to said axial direction (Z); - pivot said axis (5) relative to said component (3) to put the latter in said second relative angular orientation. CH 714 000 A1