CH707782B1 - An anchor comprising two levels forming a monobloc assembly and coaxial escapement system comprising such an anchor. - Google Patents

Abstract

The invention relates to an anchor (55) for a coaxial escapement. The anchor has a first level (50) forming a main body (55) with a fork (57), the first level (50) having a first series of vanes (56, 58). According to the invention, the anchor (55) further comprises a second level (52) forming a stinger (53) above said fork, the second level (52) having a pallet (54) above said first pallet series (56, 58). The first (50) and second (52) levels form a one-piece assembly to reduce misalignment of one level relative to the other. The invention also relates to a coaxial exhaust system (51) for a timepiece comprising such an anchor (55).

Description

Description

Field of the invention [0001] The invention relates to a monoblock anchor for a coaxial escapement and in particular such an anchor formed on two levels.

BACKGROUND OF THE INVENTION [0002] It is known to form a coaxial exhaust anchor made on three levels to cooperate with a double coaxial escapement wheel and a plate. However, it is difficult to properly reference the different parts of such an anchor between them. SUMMARY OF THE INVENTION [0003] The object of the present invention is to overcome all or part of the disadvantages mentioned above by proposing a coaxial escapement anchor, the anchor being integral, the anchor being formed on only two levels.

To do this, is proposed according to a first aspect of the invention an anchor for a coaxial escapement according to independent claim 1.

A first embodiment of the invention relates to a packed anchor according to claim 2.

A second embodiment of the invention relates to a packed anchor according to claim 3.

[0007] According to other embodiments: the packed anchor may be formed from at least one metal or at least one metal alloy; - The padded anchor can be formed based on silicon.

A second aspect of the invention relates to a coaxial exhaust system for a timepiece according to the secondary claim 7, the coaxial escapement system comprising an anchor according to the first aspect of the invention or one of its embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS [0009] Other particularities and advantages will become clear from the following description, given by way of indication and in no way limitative, with reference to the appended drawings, in which: FIGS. 1 to 4 are representations of the successive steps of a method of manufacturing an escapement anchor according to a first variant of the invention; figs. 5 to 8 are representations of the successive steps of a method of manufacturing an escapement anchor according to a second variant embodiment of the invention; fig. 9 is a perspective representation of a coaxial exhaust system according to a first embodiment of the invention; fig. 10 is a perspective representation of a coaxial escapement according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] The invention relates to an improved coaxial escapement system for a timepiece. The exhaust system 51, 61 according to the invention comprises a mobile 15 formed of a first 1 and a second 11 escape wheels. The second escape wheel 11, also called the impulse pinion, is mounted on the same axis 3 as the first escape wheel 1. The angular position of the teeth 13 of the second escape wheel 11 is indexed to the position angular teeth 8 of the first escape wheel 1.

The first escape wheel 1 has the shape of a classic Swiss anchor escapement wheel. The second escape wheel 11 also acts as an exhaust pinion meshing with an intermediate wheel of the wheel 17 of the timepiece, which has the advantage of reducing the height of the mechanism. However, a pinion can be mounted in addition to two escape wheels to mesh with the gear 17 which imposes, in this alternative, three levels to the mobile coaxial escapement.

The large plate 19 of the balance carries a plate pin 21 and a pulse pallet 23. The plate pin 21 is intended to drive, in a back-and-forth movement, the anchor 55, 65 and the impulse pallet 23 is intended to cooperate with the teeth 8 of the first escape wheel 1.

According to a first embodiment of the invention illustrated in FIG. 9, the anchor 55 is monobloc and comprises two levels 50, 52 with distinct patterns one above the other. Advantageously according to the invention, the first level 50 forms the main body of the anchor 55. It is provided with a fork 57 with two horns intended to cooperate with the pin 21 of the large plate 19. The first level 50 also includes housings adapted to receive a first series of pallets 56, 58 intended to cooperate with the teeth 8 of the escape wheel 1.

The second level 52 of the anchor 55, according to the first embodiment of the invention comprises a dart 53 mounted cantilever above the fork 57 centered between its horns. The second level 52 also comprises a base 59 made of material above the first level 50 and, in particular, having a housing adapted to receive a pallet 54 intended to cooperate with the teeth 13 of the exhaust pinion 11. It is therefore understood, according to the first embodiment of the invention illustrated in FIG. 9, that the pallet 54 is mounted above the first series of pallets 56, 58.

As explained below, the first 50 and second 52 levels form, advantageously according to the invention, a one-piece assembly in order to reduce the problems of alignment of one level with respect to the other. The pallets 54, 56, 58, preferably in ruby, only need to be mounted in the appropriate housing to mount the anchor 55 in the exhaust system 51. The anchor 55 can be, preferably, formed from at least one metal, at least one metal alloy or even silicon-based.

According to a second embodiment of the invention illustrated in FIG. 10, the anchor 65 is monobloc and comprises two levels 60, 62 with distinct patterns one above the other. Advantageously according to the invention, the first level 60 forms the main body of the anchor 65. It is provided with a fork 67 with two horns intended to cooperate with the ankle 21 of the large plate 19. The first level 60 also comprises a first series of pallets 66, 68 integral and intended to cooperate with the teeth 8 of the escape wheel 1.

The second level 62 of the anchor 65, according to the second embodiment of the invention comprises a dart 63 cantilevered above the fork 67 centered between its horns. The second level 52 also comprises a base 69 made of material above the first level 50 and, in particular, comprising a pallet 64 intended to cooperate with the teeth 13 of the escape pinion 11. It is therefore understood, according to the second embodiment of FIG. embodiment of the invention illustrated in FIG. 10, that the pallet 64 is mounted above the first series of pallets 66, 68.

As explained below, the first 60 and second 62 levels form, advantageously according to the invention, a one-piece assembly to reduce the problems of alignment of one level with respect to the other. In addition, the anchor 65 may be, preferably, formed from at least one metal, at least one metal alloy or even silicon-based.

Of course, these two embodiments of FIGS. 9 and 10 may be formed using other materials. However, an electroformable material, on the one hand, or a micro-machinable material, on the other hand, are preferred. Indeed, to date, the deep reactive ion etching and electroforming type LIGA are the only processes capable of producing parts with the precision of the order of a few microns necessary for the proper operation of the anchor 55, 65. However, any other process capable of meeting the same manufacturing tolerances is applicable.

An electroformable material may be formed with gold and / or copper and / or silver and / or indium and / or platinum and / or palladium and / or nickel without these compounds are exhaustive. Indeed, other compounds such as phosphorus can be added in a smaller amount.

A micro-machinable material may be formed by silicon carbide, crystallized silicon, crystallized alumina or crystallized silica without these compounds being equally exhaustive.

Of course, the anchor 55, 65 may also comprise resilient fixing means for mounting it to a rotation on an axis 70, 71. Such elastic means may, for example, take the form of those disclosed in the fig. 10A to 10E of EP 1 655 642 or those disclosed in FIGS. 2 to 5 of WO 2007/099 068, which documents are incorporated by reference in the present description.

Alternatively, the anchor 55, 65 may also comprise flexible means to be rotatably mounted along a virtual axis. Such flexible means may, for example, take the form of those disclosed in WO 2012/010408, which document is incorporated by reference in the present description.

It is also understood that the axis 70,71 may be integral with the anchor 55, 65 or mounted on the level of the first level 50, 60 and / or the second level 52, 62, that is, that is to say that an opening of one level could be greater than that of the other level which would comprise or not means of fixing. Similarly, nothing prevents each opening in each level includes its own fastening means.

In addition, the elastic fixing means could alternatively be replaced by plastic fixing means in particular when using boards based on a micro-machinable material. By way of example, they could be formed by a washer made of metallic material allowing the anchor 55, 65 to be driven against the axis 70, 71 by plastic deformation without subjecting the material used to form the anchor 55 to stress, 65. Of course, other plastic fixing means are possible.

Both types of manufacture will be presented respectively in FIGS. 1-4 and 5-8. FIGS. 1 to 4 present successive main stages of a micro-machining for a better understanding. Preferably, the method comprises a first step consisting in providing a substrate 31 comprising an upper layer 33 and a lower layer 35 made of micro-machinable materials which are interconnected by an intermediate layer 34. This type of substrate 31 is also known. under the abbreviation SOI from the English words "Silicon On Insulator".

In a second step, etching of at least one pattern 36 in the upper layer 33 to discover the intermediate layer 34 to form a first level 50, 60 of the anchor 55, 65. This second step thus makes it possible to form one or more first pattern (s) of the anchor 55, 65 in the upper layer 33.

As illustrated in FIG. 2, a mask 37 is formed, for example by photolithography, to protect the part of the upper layer 33 that it is desired to keep and, as illustrated by broken lines, the upper part of the substrate 31 is subjected to anisotropic etching. deep reactive ionic etching type also known as DRIE abbreviation from the words "Deep Reactive Ion Etching". As shown in fig. 3, the first pattern 36 having a first level 50, 60 of the anchor 55, 65 is obtained.

In a third step, etching of at least one second pattern 38 in the lower layer 35 to discover the intermediate layer 34 to form, in one piece with the first level 50, 60 at least one second level 52, 62 of the anchor 55, 65. This third step thus makes it possible to form one or more second pattern (s) of the anchor 55, 65 in the lower layer 35.

As illustrated in FIG. 3, a mask 39 is formed, for example by photolithography, to protect the part of the lower layer 35 that it is desired to keep and, as illustrated by broken lines, the lower part of the substrate 31 is subject to anisotropic etching. deep reactive ion etching type (DRIE). As shown in fig. 4, the second pattern 38 having at least one second level 52, 62 is obtained in a monoblock manner with the first level 50, 60 formed in the preceding steps.

It remains only to release each anchor 55, 65 on two levels thus formed of the substrate 31 and, optionally, the uncovered portions of the intermediate layer 34 to mount the anchor 55, 65 in the system of Exhaust 51, 61. Preferably, when the anchor 55, 65 is formed based on silicon, an additional oxidation step is performed to form at least a portion of silicon dioxide at its outer surface in the purpose of making it more mechanically resistant.

Figs. 5-8 present successive main steps of electroforming for better understanding. Preferably, the method comprises a first step of providing a substrate 41 having an electrically conductive upper layer. This layer can be obtained by the deposition of an electrically conductive material on an insulating material or in that the substrate is formed of an electrically conductive material.

The main steps of an electroforming consist in forming a mold and then filling the mold with a material, for example, using an electroplating. This type of electroforming is known by the abbreviation L.I.G.A. deriving from the German terms "roentgenlthography, Galvanoformung & Abformung ". There are several types of L.I.G.A. next that the multi-level mold is formed between each electroplating or is formed entirely to be, only after, filled. For the explanation below, the technique presented consists in forming each level, that is to say forming a level of the mold and filling it before going to the next level. Of course, any type of electroforming, type L.I.G.A. or not, capable of forming a monoblock anchor at least two distinct levels is possible.

As illustrated in FIGS. 5 and 6, in a first step, the first level 47 of the mold is formed using, for example, a photolithography of a resin as illustrated in FIG. 5. At least one cavity of corresponding shape is formed at a first level 50, 60, of the anchor 55, 65. Said at least one cavity is then filled by electrodeposition of a metallic material 46.

As illustrated in FIG. 7 similarly to the first time, in a second step, a second level 49 of resin is formed using, for example, also a photolithography. At least one recess of corresponding shape is formed at the second level 52, 62 of the anchor 55, 65 and communicating with said at least one cavity of the first level 47 of resin. The second level 49 of resin is then filled by electrodeposition of a metallic material 48.

It remains more than to release the anchor 55, 65 on two levels thus formed of the substrate 41 and resins 47,49 as shown in FIG. 8 to mount the anchor 55, 65 in the exhaust system 51, 61. In the example of an anchor 55, 65 obtained by electroforming, it is understood that it is no longer necessary to form the means of elastic or plastic fasteners because the metallic material can be driven directly on the axis 70, 71.

Of course, the present invention is not limited to the example shown but is susceptible of various variations and modifications that will occur to those skilled in the art within the scope of the claims. In particular, it should be understood that at least two levels are made integrally. Thus, it is perfectly conceivable that at least one additional level is formed against the first 50, 60 and / or the second levels 52, 62 to add other functional elements in one-piece fashion, such as, for example, the axis 70, 71.

In addition, the two embodiments of FIGS. 9 and 10 can be combined. It is thus understood, in particular, that a level of the first embodiment can be combined with a level of the second embodiment to form a coaxial escapement anchor which comprises at least one level of the anchor 55 and at least one other anchor level 65.

Claims (7)

Finally, other levels can be added to further space the functional elements between them. By way of non-limiting example, the stinger 53, 63 could have a base on a first level and the element cantilevered on a level above in order to further space the element bearing over the range 57, 67 to, for example, allow the use of a pin 21 higher. claims Anchor (55, 65) for a coaxial escapement having a first level (50, 60) forming a main body (55, 65) having a fork (57, 67), the first level (50, 60) comprising a first series of pallets (56, 58, 66, 68) characterized in that the anchor (55, 65) has a second level (52, 62) forming a stinger (53, 63) above said fork, the second level (52, 62) having a pallet (54, 64) above said first pallet series (56, 58, 66, 68), the first (50, 60) and second (52, 62) levels forming a one-piece assembly to reduce alignment problems from one level to the other. 2. Anchor (55) according to the preceding claim, characterized in that the first level (50) comprises housings adapted to receive said first series of pallets (56, 58) and the second level (52) comprises a housing adapted to receive said pallet (54), the second level housing (52) being arranged above the first level housing (50). 3. Anchor (65) according to claim 1, characterized in that the first series of pallets (66, 68) of the first level (60) is integral with this first level (60) and the pallet (64) of the second level (62) has come from matter with this second level (62). 4. Anchor (65) according to the preceding claim, characterized in that it is monobloc. 5. Anchor (55, 65) according to one of claims 1 to 4, characterized in that it is formed from at least one metal or at least one metal alloy. 6. Anchor (55, 65) according to one of claims 1 to 5, characterized in that it is formed based on silicon. 7. coaxial escapement system (51, 61) for a timepiece, characterized in that it comprises an anchor (55, 65) according to one of claims 1 to 6, said anchor cooperating with a mobile (15 ) having a first escape wheel coaxial with a second escape wheel (11), the first series of pallets (56, 58, 66, 68) of the anchor (55, 65) co-operating with the first escapement wheel (1) of the mobile (15), the pallet (54, 64) of the second level of the anchor (55, 65) cooperating with the second escape wheel (11) of the mobile (15).