EP2977835B1 - Welding by electroforming an electroformed timepiece shell - Google Patents

Description

Field of the invention

The invention relates to a method for manufacturing an electro-formed component of a clockwork structure.

The invention also relates to an electro-formed component of a clockwork structure produced according to such a method.

The invention relates to the field of watch structure components, and more particularly to thin components made of precious alloys, in particular gold.

Background of the invention

The manufacture of electroforming watch structure components makes it possible to obtain a perfect geometry, a good surface condition, and an impeccable appearance, while consuming little expensive material, because of the small thickness of the pieces thus produced. In the case of dressing components (boxes, links, glasses, and the like), the parts obtained are recessed hulls, the mechanical properties of which must be validated according to the application,

The resistance of such shells is related to their geometry, and it is clear that to obtain a fairly rigid shell, having ribs, or stiffening tubes, it is necessary to machine beforehand a core-shaped substrate of fairly complex shape. and thus costly realization. Failing this, a hull with low stiffness resists badly with other components, such as a bottom, horns, a bracelet, or other, and risk, in the best case to deform to a detrimental extent to the sealing of the timepiece in which this shell will be incorporated, or in the worst case of tearing or cracking.

The document CH692531 in the name of MAYOR describes a watch case formed of a thin metal wall, of substantially constant thickness. The wall defines, in a spectacle portion, a cylindrical surface which circumscribes an upper opening closed by an ice fixed by a seal to this wall, and a groove open on a receiving housing of a movement. A retaining ring is removably attached in this groove.

The document EP0762240A1 in the name of SONCEBOZ SA blanks factory describes a box with a hollow housing and a casing ring, with a thin-walled electro-formed middle of precious metal, defining a concave inner face. The casing ring, made of a less expensive material, is introduced into the middle part of a base removably assembled to the middle part, a recess separating it from the internal face, and is held there by compression between surfaces of lower and upper support, respectively defined by a portion of the inner face of the bottom, and a portion of the inner face of the middle part. The document EP0716360A1 In the name of SONCEBOZ SA drafts factory describes a similar watch case where the lower and upper bearing surfaces are parallel to the bottom, and where, the casing ring can have a variable thickness when introduced or in position service, under the effect of mechanical means or its own elasticity.

The document EP1742120 A2 in the name of RICHEMONT describes a watch comprising a housing with a fixed part and a movable part which comprises a middle part and a movement pivotally mounted on the fixed part along a pivot axis by pivots for effecting a tilting movement of the movable part in two opposite directions, effected by a pressure on a portion of the movable part. At least one actuating mechanism cooperates with the fixed and movable parts to transform their relative tilting into an action on a control member accessible from outside the movement and intended to activate at least one function.

Summary of the invention

The invention proposes to overcome these problems and to produce an improved structural stiffness component.

For this purpose, the invention relates to a method for manufacturing an electro-formed component of a clockwork structure according to claim 1.

Brief description of the drawings

• la figure 1 représente, de façon schématisée et en coupe, un substrat sacrificiel mis en oeuvre dans le procédé selon l'invention, dans lequel un insert massif en alliage ou métal précieux est assemblé dans un logement dans ce substrat, lequel substrat est partiellement recouvert par une épargne ; l'insert comporte ici un perçage également protégé par une épargne ; cet ensemble constitue un substrat sacrificiel équipé, protégé par les épargnes, et destiné à être utilisé comme noyau d'électroformage ;
• la figure 2 représente, de façon similaire, le résultat, après une opération de dépôt, par une opération d'électroformage, du même alliage ou métal précieux que celui qui constitue l'insert, après dégagement des épargnes, et avant destruction du substrat sacrificiel; à ce stade une coque électro-formée recouvre le substrat dans les zones non épargnées, et recouvre aussi l'insert au niveau de sa surface accessible ;
• la figure 3 représente, de façon similaire, le composant électro-formé brut obtenu ensuite par destruction du substrat sacrificiel, et exécution d'un usinage de finition dans l'insert au travers de la partie de la coque électro-formée qui le recouvre, cet usinage étant ici un taraudage ; la figure 4 montre un détail de cette zone, qui est voisine d'une surface de réception d'un joint d'étanchéité ;
• la figure 7 représente une variante avec un insert comportant une surface fonctionnelle à proximité immédiate d'une cloison interne, impossible à réaliser par usinage, et facile à réaliser avec l'invention.

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 represents, diagrammatically and in section, a sacrificial substrate used in the process according to the invention, in which a solid insert of alloy or precious metal is assembled in a housing in this substrate, which substrate is partially covered by a saving ; the insert here includes a bore also protected by savings; this assembly constitutes a sacrificial substrate equipped, protected by savings, and intended to be used as an electroforming core;
• the figure 2 similarly represents the result, after a deposition operation, by an electroforming operation, of the same alloy or precious metal as that which constitutes the insert, after release of the savings, and before destruction of the sacrificial substrate; at this stage, an electro-formed shell covers the substrate in the non-spared areas, and also covers the insert at its accessible surface;
• the figure 3 represents, in a similar way, the crude electro-formed component subsequently obtained by destroying the sacrificial substrate, and performing a finishing machining in the insert through the portion of the electro-formed shell which covers it, this machining being here a tapping; the figure 4 shows a detail of this area, which is close to a receiving surface of a seal;
• 7 shows a variant with an insert having a functional surface in the immediate vicinity of an internal partition, impossible to achieve by machining, and easy to achieve with the invention.

Detailed Description of the Preferred Embodiments

The invention proposes to produce an electro-formed component of a clockwork structure, and therefore of rather reduced thickness, of the order of a few tenths of a millimeter, and nevertheless comprising reinforced zones that are sufficiently solid to receive fastening elements. , closing, fastening, decorating, or the like, these reinforced areas having sufficient rigidity to absorb the torsional and / or tensile and / or shear forces exerted by fastening means or the like, to ensure impact resistance appropriate, and to avoid any deformation or tear of the electro-formed shell forming the bulk of the structural component considered, as well as to have an appropriate shock resistance.

The invention still proposes to make components with functional geometries impossible to achieve by traditional machining, particularly in areas of reduced accessibility or zero for a conventional tool.

For this purpose, the invention relates to a method for manufacturing a component of electro-shaped watch structure 1.

• on choisit un même premier alliage comportant un premier métal précieux pour réaliser, d'une part des inserts 3 fonctionnels massifs, et d'autre part une coque électro-formée 2;
• on réalise les inserts 3 par des méthodes traditionnelles bien connues;
• on réalise un substrat 4 d'électroformage, de profil complémentaire au profil intérieur du composant 1, dans un deuxième matériau sacrificiel;
• on réalise, pour recevoir chaque insert 3, un logement 5 dans le substrat 4 ;
• on insère les inserts dans les logements 5 correspondants réalisés sur le substrat 4, pour réaliser un substrat sacrificiel équipé 6 ;
• on équipe ce substrat sacrificiel équipé 6 des épargnes 9 nécessaires pour obtenir, par un procédé d'électroformage, un composant électro-formé brut 7, avec dépôt de matière sur le substrat 4 servant de noyau pour réaliser la coque électro-formée 2, ainsi que sur chaque surface accessible de chaque insert 3 pour le solidariser avec la coque électro-formée 2;
• on effectue cet électroformage ;
• on dégage les épargnes 9
• on détruit le substrat 4.

According to the invention, the following operations are carried out:

• a same first alloy comprising a first precious metal is chosen to produce, on the one hand, solid functional inserts 3, and on the other hand an electro-formed shell 2;
• the inserts 3 are made by well-known traditional methods;
• an electroforming substrate 4, of complementary profile to the inner profile of the component 1, is produced in a second sacrificial material;
• to receive each insert 3, a housing 5 is formed in the substrate 4;
• the inserts are inserted in the corresponding recesses 5 made on the substrate 4, to produce a sacrificial substrate equipped with 6;
• this sacrificial substrate equipped with the savings 9 required is equipped to obtain, by an electroforming process, a raw electro-formed component 7, with deposition of material on the substrate 4 serving as a core for producing the electro-formed shell 2, and that on each accessible surface of each insert 3 to secure it with the electro-formed shell 2;
• this electroforming is carried out;
• the savings are released 9
• the substrate 4 is destroyed.

Preferably, the first alloy comprising a first precious metal with a title at least equivalent to that stamped on the finished component is chosen.

• on l'applique à la fabrication d'un composant de structure 1 d'horlogerie électro-formé creux et de profil donné et comportant une coque électro-formée 2 d'épaisseur sensiblement constante, et:
• on définit au moins un insert 3 destiné à être incorporé dans le composant 1 par soudage par électro-formage avec la coque électro-formée 2 ;
• on choisit un premier métal parmi une première famille, dite de métal précieux, comportant l'or, l'argent, le platine, le rhodium, l'osmium, le palladium, le ruthénium, l'iridium, le titane, le zirconium, et le tantale ;
• on choisit un même dit premier alliage comportant au moins un tel premier métal pour réaliser, d'une part chaque dit insert 3, et d'autre part la coque électro-formée 2;
• on réalise chaque dit insert 3 dans le premier alliage, de façon massive;
• - on choisit, pour réaliser un substrat sacrificiel 4 d'électroformage, un deuxième matériau sacrificiel, ou bien parmi les alliages d'une deuxième famille comportant le cuivre, l'étain, le nickel, le zinc, l'aluminium, le magnésium, le plomb, le manganèse, le chrome, l'arsenic et le fer, ou bien constitué d'une matière polymère chargée de particules conductrices, et/ou recouverte d'une couche conductrice;
• on réalise, dans le deuxième matériau, un dit substrat sacrificiel 4 selon un profil complémentaire au profil intérieur du composant de structure 1;
• on réalise sur le substrat sacrificiel 4 un logement 5 de réception de chaque dit insert 3 ;
• on insère ou on chasse chaque dit insert 3 dans son dit logement 5 correspondant, de façon à réaliser un substrat sacrificiel équipé 6;
• on dispose sur le substrat sacrificiel équipé 6 destiné à être utilisé comme noyau d'électroformage la ou les épargnes 9 nécessaires pour l'obtention d'un composant électro-formé brut 7;
• on met en oeuvre un procédé d'électroformage pour obtenir un composant électro-formé brut 7 avec les sections de matière requises au niveau de la coque électro-formée 2, avec dépôt de matière sur le substrat sacrificiel 4 servant de noyau, et avec dépôt de matière sur chaque surface accessible de chaque insert 3, solidarisant ainsi chaque insert 3 avec la coque électro-formée 2 ; - on détruit le substrat sacrificiel 4 et on dégage toutes les épargnes 9.

More particularly, in a preferred implementation of this method, the following steps are carried out:

• it is applied to the manufacture of a component of hollow electro-formed clockwork structure 1 and of given profile and comprising an electro-formed shell 2 of substantially constant thickness, and:
• at least one insert 3 intended to be incorporated in the component 1 by electroforming welding with the electro-formed shell 2 is defined;
• a first metal is selected from a first family, referred to as a precious metal, comprising gold, silver, platinum, rhodium, osmium, palladium, ruthenium, iridium, titanium, zirconium, and tantalum;
• a same said first alloy comprising at least one such first metal is chosen to produce, on the one hand each said insert 3, and on the other hand the electro-formed shell 2;
• each said insert 3 is made in the first alloy, in a massive manner;
• a second sacrificial material is chosen, for producing an electroforming sacrificial substrate 4, or among the alloys of a second family comprising copper, tin, nickel, zinc, aluminum, magnesium, lead, manganese, chromium, arsenic and iron, or made of a polymer material loaded with conductive particles, and / or covered with a conductive layer;
• in the second material, a so-called sacrificial substrate 4 is formed according to a profile complementary to the internal profile of the structure component 1;
• a housing 5 for receiving each said insert 3 is made on the sacrificial substrate 4;
• each said insert 3 is inserted or driven into its said corresponding housing 5, so as to produce an equipped sacrificial substrate 6;
• there is disposed on the sacrificial substrate equipped 6 for use as an electroforming core or savings 9 necessary for obtaining a crude electro-formed component 7;
• an electroforming process is used to obtain a raw electro-formed component 7 with the required sections of material at the electro-formed shell 2, with deposition of material on the sacrificial substrate 4 serving as a core, and with deposition of material on each accessible surface of each insert 3, thereby securing each insert 3 with the electro-formed shell 2; the sacrificial substrate 4 is destroyed and all the savings 9 are released.

In particular, before destroying the sacrificial substrate 4 and / or clearing the savings 9, at least one machining operation is performed on at least one such insert 3, and on the portion of the electro-formed shell 2 which covers locally.

In a variant, after destroying the sacrificial substrate 4 or / and clearing the savings 9, at least one machining operation is performed on at least one such insert 3 and on the part of the electro-formed shell 2 which covers it locally. .

According to a particular variant of the invention, a brass or zamak is chosen as the second sacrificial material.

In another variant, the sacrificial substrate is made of a polymer material loaded with conductive particles, or of polymer material covered with a conductive layer by a well-known "electroless" process.

In a particular variant of the invention, such an electro-forming process is used to obtain a raw electro-formed component by growth of material both outwardly and inwardly of the sacrificial substrate, with the sections of matter required.

In another variant of the invention, the sacrificial substrate is not necessarily an alloy, and it comprises at least one electrically conductive material, or coated with a conductive layer of electricity. This sacrificial substrate may in particular comprise at least one polymer material loaded with conductive particles, and / or covered with a conductive layer by a well-known "electroless" method, or the like, or comprise a plastic loaded in a similar manner. The other steps of the process can be carried out similarly to the method described above with a sacrificial alloy, only differs the mode of elimination of this sacrificial substrate.

According to a particular variant of the invention, a gold or platinum alloy is chosen as the first alloy.

More particularly, an alloy having at least 75% by weight of gold is advantageously chosen as the first alloy.

Naturally the invention is applicable to any title of precious metal alloy, for example to a 14 K gold alloy, in countries where these alloys are more common than 18K alloys above.

According to a particular variant of the invention, the electro-formed shell 4 is made with sections of material between 0.25 and 0.35 mm. Naturally, for some applications such as decorations, preferably in superposition, the thickness may be less than the value of 0.25 mm, which is preferred for components requiring good mechanical strength.

According to a particular variant of the invention, at least one such insert 3 is made with a pre-drilling 32.

According to a particular variant of the invention, the diameter of the pre-drilling 32 is chosen as a function of the thickness of the first alloy deposited during the electroforming operation, in order to obtain at the level of the insert 3 concerned, in the raw electro-formed component 7, a diameter compatible with a finishing of the machining of this insert 3 by tapping by deformation or by removal of chips.

According to a particular variant of the invention, the pre-drilling 32 is equipped with a saver 9, possibly threaded beforehand or having a similar machining allowing its easy extraction, before performing the electroforming operation.

According to a particular variant of the invention, each said insert 3 is produced with its smallest dimension at least greater than five times the thickness of the first alloy deposited during the electroforming operation.

More particularly, this structural component 1 constitutes a middle part 20.

FIG. 7 illustrates a variant with an insert 3, comprising a functional surface 33, in the immediate vicinity of an internal partition 21, impossible to produce by machining, and easy to implement with the invention.

This timepiece 100 is in particular a watch.

Claims (13)

1. Method for manufacturing an electroformed structural timepiece component (1), characterized in that the following steps are performed:

   - the same first alloy including a first precious metal is selected to make both functional inserts (3) and an electroformed shell (2);

   - said inserts (3) are made;

   - an electroforming substrate (4) having a complementary profile to the inner profile of said component (1) is formed in a second sacrificial material;

   - said inserts are inserted into housings (5) made on said substrate (4), to form an equipped sacrificial substrate (6), which is provided with the resists (9) necessary to obtain, by means of an electroforming process, a bare electroformed component (7), with deposition of material on said substrate (4), acting as a core to form said electroformed shell (2), and on each accessible surface of each insert (3) to secure the insert to said electroformed shell (2);

   - the resists (9) are removed;

   - said substrate (4) is destroyed.
2. Method according to claim 1, characterized in that:

   - the method is applied to the manufacture of a hollow, electroformed, structural timepiece component (1) with a given profile and including an electroformed shell (2) of substantially constant thickness, and in that:

   - there is defined at least one insert (3) intended to be incorporated in said component (1) by electroform welding with electroformed shell (2);

   - a first metal is selected from a first family including gold, silver, platinum, rhodium, osmium, palladium, ruthenium, iridium, titanium, zirconium, and tantalum;

   - said same first alloy including at least one said first metal is selected to from both each said insert (3) and said electroformed shell (2);

   - each said insert (3) is formed solidly of said first alloy;

   - to make a sacrificial electroform substrate (4), a second sacrificial material is selected, either from the alloys of a second family including copper, tin, nickel, zinc, aluminium, magnesium, lead, manganese, chromium, arsenic and iron, or formed of a polymer charged with conductive particles, and/or coated with a conductive layer;

   - a said sacrificial substrate (4) having a complementary profile to the inner profile of said structural component (1) is formed in said second material;

   - a housing (5) for receiving each said insert (3) is made on said sacrificial substrate (4);

   - each said insert (3) is inserted or driven into its said corresponding housing (5), so as to form an equipped sacrificial substrate (6);

   - the resist or resists (9) necessary to obtain a bare electroformed component (7) are arranged on said equipped sacrificial substrate (6) intended to be used as an electroforming core;

   - an electroforming process is implemented to obtain a bare electroformed component (7) with the required sections of material on said electroformed shell (2), with deposition of material on said sacrificial substrate (4) acting as a core, and with deposition of material on each accessible surface of each said insert (3), thereby securing each said insert (3) to said electroformed shell (2);

   - said sacrificial substrate (4) is destroyed and all the resists (9) are removed.
3. Method according to claim 2, characterized in that a brass or zamak is chosen as said second material.
4. Method according to claim 1, characterized in that:

   - the method is applied to the manufacture of a hollow, electroformed, structural timepiece component (1) with a given profile and including an electroformed shell (2) of substantially constant thickness, and in that:

   - there is defined at least one insert (3) intended to be incorporated in said component (1) by electroform welding with said electroformed shell (2);

   - a first metal is selected from a first family including gold, silver, platinum, rhodium, osmium, palladium, ruthenium, iridium, titanium, zirconium, and tantalum;

   - said same first alloy including at least one said first metal is selected to from both each said insert (3) and said electroformed shell (2);

   - each said insert (3) is formed solidly of said first alloy;

   - there is selected a second electrically conductive material including at least one polymer substrate charged with conductive particles and/or coated with a conductive layer;

   - there is selected a second said sacrificial material including at least one said second metal to form a sacrificial electroform substrate (4);

   - a said sacrificial substrate (4) having a complementary profile to the inner profile of said structural component (1) is formed in said second material;

   - a housing (5) for receiving each said insert (3) is made on said sacrificial substrate (4);

   - each said insert (3) is inserted or driven into its said corresponding housing (5), so as to form an equipped sacrificial substrate (6);

   - the resist or resists (9) necessary to obtain a bare electroformed component (7) are arranged on said equipped sacrificial substrate (6) intended to be used as an electroforming core;

   - an electroforming process is implemented to obtain a bare electroformed component (7) with the required sections of material on said electroformed shell (2), with deposition of material on said sacrificial substrate (4) acting as a core, and with deposition of material on each accessible surface of each said insert (3), thereby securing each said insert (3) to said electroformed shell (2);

   - said sacrificial substrate (4) is destroyed and all the resists (9) are removed.
5. Method according to any of claims 1 to 4, characterized in that, before destroying said sacrificial substrate (4) and/or removing the resists (9), at least one machining operation is performed on at least one said insert (3) and on the part of said electroformed shell (2) which covers the insert locally.
6. Method according to any of claims 1 to 5, characterized in that, after having destroyed said sacrificial substrate (4) and/or removed the resists (9), at least one machining operation is performed on at least one said insert (3) and on the part of said electroformed shell (2) which covers the insert locally.
7. Method according to any of claims 1 to 6, characterized in that a gold or platinum alloy is selected as said first alloy.
8. Method according to claim 7, characterized in that an alloy including at least 75% by mass of gold is selected as said first alloy.
9. Method according to any of claims 1 to 8, characterized in that said electroformed shell (2) is made with sections of material comprised between 0.25 and 0.35 mm.
10. Method according to any of claims 1 to 9, characterized in that at least one said insert (3) is made with a pre-pierced hole (32).
11. Method according to claim 10, characterized in that the diameter of said pre-pierced hole (32) is selected as a function of the thickness of said first alloy deposited during said electroforming, to obtain on said at least one insert (3) in said bare electroformed component (7), a diameter compatible with finish machining of said insert (3) by forming internal threads by tapping.
12. Method according to claim 10, characterized in that said pre-pierced hole (32) is provided with a said resist (9) before said electroforming operation is performed.
13. Method according to any of claims 1 to 12, characterized in that each said insert (3) is made with the smallest dimension thereof at least five times greater than the thickness of said first alloy deposited during said electroforming.

Images