EP3339970B1 - Timepiece dial made of a light metal alloy material - Google Patents

Description

Field of the invention

The invention relates to a timepiece dial 1 comprising a flange 2 whose material is a first alloy, comprising on a first side at least one display area 3 visible by a user, and on a second side at least one foot 4 for positioning and/or fixing said dial 1 in a timepiece movement 100, wherein said flange 2 comprises at least one receiving zone 5 complementary to an end zone 6 of at least one said foot 4 which is a weldable foot 40 arranged to be welded or brazed with said flange 2 at the interface between said reception zone 5 and said end zone 6, and of which the material of said weldable foot 40 is a second weldable or brazable alloy with said first alloy, at least one said reception zone 5 enveloping a said respective end zone 6 relating to the assembly of the same said weldable foot 40, or at least one said end zone 6 enveloping a said respective reception zone 5 relating to the ssemblage of the same said weldable foot 40, or at least a pair formed of a said end zone 6 and a said complementary reception zone 5 comprising, in a first assembled state not welded or brazed, a thread cooperating with a thread. According to the invention, the first alloy is an aluminum alloy, and the second alloy is a titanium alloy, or vice versa.

The invention also relates to a one-piece dial assembly, the material of which is an alloy of aluminum and titanium, comprising such a dial.

The invention relates to the field of display components for watchmaking or for scientific instruments or measuring devices.

Background of the invention

Clockwork or scientific instrument dials have feet for fixing and/or positioning on a plate or in a movement.

Often these feet are useful for the dial manufacturing process, for attaching supports or for making deposits in galvanic baths, performing the dual function of holding element and current guide.

In general, these feet are made of copper, coated with a fine deposit of gold to prevent their oxidation and improve their electrical contact. The dials are generally made of copper, brass, nickel silver or similar alloy, so the behavior during the different stages of the process is the same on the dial and the feet that it comprises.

The resistance welding process makes it possible to join these feet and dial, by subjecting them to an energy pulse in the direction of the foot, this energy locally melting the metal at the interface of the dial and the foot, at one end of the foot called the pivot, which is of a defined diameter, often smaller than the diameter of the foot, over a defined height, and which constitutes a fusible element which ensures the connection with the dial.

But such copper alloy feet are not suitable for making dials made of certain light alloys, in particular aluminum alloys. In fact, copper alloy feet dissolve during electrochemical conversion processes, such as anodization, anodic oxidation or the like, in baths or electrolytes comprising sulfuric or sulfonitric acid.

It is therefore desirable to produce feet in a material exhibiting the same behavior as the material of the dial. A one-piece production of the feet with the flange of the dial is costly in machining by milling, or difficult to achieve by stamping.

For this reason it is not uncommon to see dials in light alloy comprising a flange undergoing all the galvanic treatments, on which are then added feet in copper alloy. Or even dials without feet, fixed by fins on the movement.

The document US3 803 832 A in the name of SHIMIZU describes a watch dial comprising a body formed from a flat aluminum plate and rivets forming rod elements made of aluminum material, and forming fasteners on a movement. The head of each rod is shaped to fit into a recess formed on the rear surface of the body, and is integrally secured to the recess by means of ultrasonic welding. One manufacturing method uses an ultrasonic welding machine to integrally join the head and the recess.

The document CH 332 878 A on behalf of RIHS describes a process for manufacturing a dial from a sheet by stamping, in particular for the formation of numerals in relief, and by cutting, following which the numerals in relief are rectified, the front plate is chemically polished of it applies rune anodic oxidation with at least one coloring product.

The document EP2400354 on behalf of The Swatch Group Research and Development Ltd describes a dial comprising a foot made of metallic material used to attach said dial to a timepiece.

The document CH343312 in the name of Beyeler and Cie describes a process for manufacturing a metal dial comprising studs on which dial feet are welded.

Summary of the invention

The invention proposes to attach feet in aluminum alloy or titanium, on a bare dial flange in aluminum or titanium alloy, to transform this bare dial into a dial assembly comprising feet rigidly secured to this flange , and exhibiting the same chemical behavior as it.

To this end, the invention relates to a timepiece dial according to claim 1.

The invention also relates to a one-piece dial assembly, according to claim 2.

Brief description of the drawings

• la figure 1 représente, de façon schématisée, et en coupe, un cadran nu assemblé mais non soudé ni brasé, comportant un flasque avec, à l'opposé d'une surface supérieure d'affichage, une surface inférieure sur laquelle sont présentés des pieds destinés à être soudés ou brasés sur ce flasque;
• la figure 2 représente, de façon schématisée, et en coupe, un détail d'un tel cadran nu où la jonction entre le pied et le flasque est une surface plane ;
• la figure 3 représente, de façon schématisée, et en coupe, un détail d'un tel cadran nu où la jonction entre le pied et le flasque est un emboîtement cylindrique, le pied pénétrant dans un alésage du flasque;
• la figure 4 représente, de façon schématisée, et en coupe, un détail d'un tel cadran nu où la jonction entre le pied et le flasque est un point de touche entre un léger relief que comporte le flasque et un logement que comporte le pied ;
• la figure 5 représente, de façon schématisée, et en coupe, un détail d'un tel cadran nu où la jonction entre le pied et le flasque est une liaison vissée entre une entrée de taraudage que comporte le flasque, et un filetage que comporte le pied;
• la figure 6 représente, de façon schématisée, et en coupe, un tel cadran nu où la jonction entre le pied et le flasque est au niveau d'une rainure de révolution que comporte le flasque, qui porte une encoche en U que comporte le pied ;
• la figure 7 représente, de façon schématisée, et en coupe, un détail d'un tel cadran nu où la jonction entre le pied et le flasque est au niveau d'une gorge de révolution que comporte le flasque, qui reçoit un tenon droit à faces parallèles que comporte le pied ;
• la figure 8 représente, de façon schématisée, un ensemble cadran assemblé de façon irréversible par soudage ou brasage;
• la figure 9 représente, de façon schématisée, une montre comportant un tel ensemble cadran ;
• la figure 10 représente, de façon schématisée, un instrument de mesure ou appareil scientifique comportant un tel ensemble cadran.

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

• the figure 1 represents, schematically, and in section, a bare dial assembled but not welded or brazed, comprising a flange with, opposite an upper display surface, a lower surface on which are presented feet intended to be welded or brazed to this flange;
• the figure 2 represents, schematically, and in section, a detail of such a bare dial where the junction between the foot and the flange is a flat surface;
• the picture 3 represents, schematically, and in section, a detail of such a bare dial where the junction between the foot and the flange is a cylindrical socket, the foot penetrating into a bore of the flange;
• the figure 4 represents, schematically, and in section, a detail of such a bare dial where the junction between the foot and the flange is a point of contact between a slight relief that comprises the flange and a housing that comprises the foot;
• the figure 5 represents, schematically, and in section, a detail of such a bare dial where the junction between the foot and the flange is a screwed connection between a tapping entry that comprises the flange, and a thread that comprises the foot;
• the figure 6 represents, schematically, and in section, such a bare dial where the junction between the foot and the flange is at the level of a groove of revolution that includes the flange, which carries a U-shaped notch that includes the foot;
• the figure 7 represents, in a schematic way, and in section, a detail of such a bare dial where the junction between the foot and the flange is at the level of a groove of revolution that comprises the flange, which receives a straight tenon with parallel faces that comprises the foot;
• the figure 8 represents, schematically, a dial assembly irreversibly assembled by welding or brazing;
• the figure 9 represents, schematically, a watch comprising such a dial assembly;
• the figure 10 represents, schematically, a measuring instrument or scientific apparatus comprising such a dial assembly.

Detailed Description of Preferred Embodiments

The invention relates to a clock dial 1 whose material is a light alloy, comprising a flange 2 whose material is a first light alloy.

More particularly, this dial 1 is flat, or substantially flat, or with a radius of curvature greater than 30 mm.

This flange 2 comprises, on a first side at least one display area 3 visible to a user, and on a second side opposite the first side on the front and called back at least one foot 4 for positioning and/or fixing the dial 1 in a clockwork 100.

This dial 1 is a dial whose components, in particular the feet 4, are removable.

The flange 2 comprises at least one receiving zone 5 complementary to an end zone 6 of at least one foot 4, which is a weldable foot 40, which is arranged to be welded or brazed with the flange 2 at the level of the interface between the reception zone 5 and the end zone 6. The constituent material of such a weldable foot 40 is a second light alloy which is weldable or brazable with the first light alloy.

In a variant of the invention, at least one receiving zone 5 envelopes a respective end zone 6 relating to the assembly of the same weldable foot 40.

In another variant of the invention, at least one end zone 6 envelopes a respective reception zone 5 relating to the assembly of the same weldable foot 40.

In yet another variant of the invention, at least one pair formed by an end zone 6 and a complementary reception zone 5 comprises, in a first assembled state that is neither welded nor brazed, an internal thread cooperating with a thread .

In yet another variant, at least one reception zone 5 is part of a groove or a rib of revolution, in particular produced during machining of the flange 2 by turning, and the end zone 6 which is complementary to it is a part of a rib or groove of complementary revolution.

More particularly, the first alloy is an aluminum alloy, and the second alloy is a titanium alloy, or vice versa.

The aluminum alloys are preferably chosen from among the most easily weldable aluminum alloys. More particularly and without limitation, they are chosen from aluminum alloys without structural hardening, families 1000 (without addition element) and more particularly 1050 O in the annealed state, 3000 (with addition of manganese) and more particularly the 3003 O in the annealed state, 5000 (with addition of magnesium) which welds well and is well suited to anodizing, and more particularly the 5086 O in the annealed state or even the hardened and stabilized 5083 H111.

In a variant, the first light alloy is an aluminum alloy and the second light alloy is a titanium alloy, such as TiO ₂ , TiAl ₆ V ₄ called TA6V, or similar. Either the second light alloy is an aluminum alloy, and the first light alloy is a titanium alloy, such as TiO ₂ , TiAl ₆ V ₄ called TA6V, or similar.

In a variant not forming part of the invention, the first light alloy is an aluminum alloy, and the second light alloy is a magnesium alloy which is welded well with aluminum, such as MgAl _e Zn ₃ says G-A6Z3, or MgAl ₉ Zn says G-A9Z, or MgZn ₅ Th ₂ Zr, or MgZr. The reverse configuration is of course possible.

The invention also relates to a one-piece dial assembly 10, the material of which is an alloy of aluminum and titanium, comprising a bare dial 1, and which results from the transformation of this dial 1 by at least one welding or brazing operation. which irreversibly secures the flange 2 and all or part of the feet 4. The welded or brazed connection zone no longer contains any trace of the initial geometry of the end zones 6 and of the complementary reception zones 5 concerned by the operation of welding or brazing.

Thus, according to the invention, in at least one pair formed by an end zone 6 and a complementary reception zone 5, the end zone 6 and the reception zone 5 are joined in an unremovable manner at the level a welded or brazed connection between the flange 2 and the weldable foot 40 concerned.

There are, for this purpose, technologies compatible with the micro-welding of aluminum and/or titanium, in a very specific way in order to avoid any deformation of the visible display zone 3, in laser or plasma technology, with very small diameters of heated zones, of the order of 100 microns, and reduced heating. These technologies make it possible to weld or braze such a weldable foot 40 made of light alloy, in particular welded aluminum or titanium, in butt or spot welding, and in particular by laser, or plasma, or ultrasound.

More particularly 6, in each pair formed of an end zone 6 and a complementary reception zone 5, the end zone 6 and the reception zone 5 are joined in an unremovable manner at the level of a welded connection. or brazed between the flange 2 and the weldable foot 40 concerned.

In an advantageous variant, the one-piece dial assembly 10 comprises an anodized surface layer, or a surface layer of chromic or sulfuric anodic oxidation, the corresponding surface treatment being carried out after the welding or brazing operation(s).

The invention also relates to a watch 1000 comprising such a dial assembly 10.

The invention also relates to a scientific instrument comprising such a dial assembly 10.

The invention also relates to a measuring device comprising such a dial assembly 10.

• réaliser, dans un premier état assemblé non soudé ni brasé, un cadran 1 d'horlogerie dont le matériau est un alliage léger, comportant un flasque 2 dont le matériau est un premier alliage léger, comportant sur un premier côté au moins une zone d'affichage 3 visible par un utilisateur, et sur un deuxième côté opposé au premier côté au recto et appelé verso au moins un pied 4 pour le positionnement et/ou la fixation du cadran 1 dans un mouvement d'horlogerie 100. Ce flasque 2 comporte au moins une zone de réception 5 complémentaire à une zone d'extrémité 6 d'au moins un pied 4, lequel est un pied soudable 40 agencé pour être soudé ou brasé avec le flasque 2 au niveau de l'interface entre la zone de réception 5 et la zone d'extrémité 6. Et le matériau constitutif d'un tel pied soudable 40 est le premier alliage léger, ou bien un deuxième alliage léger soudable ou brasable avec le premier alliage léger ;
• assembler de façon irréversible par soudage ou brasage au moins un pied soudable 40 au flasque 2 pour constituer cet ensemble cadran 10 monobloc.

According to a method of manufacturing a one-piece watch dial assembly 10 whose material is a light alloy, the method not forming part of the invention, the following steps are carried out in this order:

• produce, in a first assembled state that is not welded or brazed, a watch dial 1 whose material is a light alloy, comprising a flange 2 whose material is a first light alloy, comprising on a first side at least one zone of display 3 visible to a user, and on a second side opposite the first side on the front and called the back at least one foot 4 for positioning and/or fixing the dial 1 in a clockwork movement 100. This flange 2 comprises at at least one reception zone 5 complementary to an end zone 6 of at least one foot 4, which is a weldable foot 40 arranged to be welded or brazed with the flange 2 at the interface between the reception zone 5 and the end zone 6. And the constituent material of such a weldable foot 40 is the first light alloy, or else a second light alloy weldable or brazable with the first light alloy;
• assembling irreversibly by welding or brazing at least one weldable foot 40 to the flange 2 to form this one-piece dial assembly 10.

More particularly, the dial is produced in one plane, or substantially plane, or with a radius of curvature greater than 30 mm,

More particularly, each weldable foot 40 is assembled irreversibly by welding or brazing to the flange 2.

More particularly, the dial 1 is made before welding or brazing with at least one receiving zone 5 which envelops, in the first assembled state not welded or brazed, a respective end zone 6 relating to the assembly of the same weldable foot 40 .

More particularly, the dial 1 is produced before welding or brazing with at least one end zone 6 which envelops, in the first assembled state, not welded or brazed, a respective reception zone 5 relating to the assembly of the same weldable foot 40 .

More particularly, the dial 1 is produced before welding or brazing with at least one pair, formed of an end zone 6 and a reception zone 5 complementary, which comprises, in the first assembled state not welded or brazed, an internal thread cooperating with a thread.

More particularly, after the irreversible assembly by welding or brazing, an anodizing operation, or chromic or sulfuric anodic oxidation, is carried out on the surface layer of the dial assembly 10.

According to the invention, the first light alloy is chosen, which is an aluminum alloy, and the second light alloy, which is a titanium alloy, or vice versa.

The particular choice of a first light alloy and a second light alloy which are two aluminum alloys is advantageous for the application of an anodizing process, but does not form part of the invention.

The alternative of titanium alloy feet gives the same capabilities, with the advantage of great dimensional stability regardless of the number of treatments applied. This alternative is favorable to the application of different chemical conversion treatments on the same dial.

Welding or brazing the feet at the start of the cycle avoids the risk of scrap at the end of production when the product has reached its maximum value.

Claims (5)

1. A timepiece dial (1) including a flange (2) whose material is a first alloy, including on a first side at least one display zone (3) visible to a user, and on a second side at least one foot (4) for positioning and/or fastening said dial (1) in a horological movement (100), wherein said flange (2) includes at least one reception zone (5) complementary to an end zone (6) of at least one said foot (4) which is a solderable foot (40) arranged to be soldered or brazed with said flange (2) at the interface between said reception zone (5) and said end zone (6), and whose material of said solderable foot (40) is a second alloy which is solderable or brazable with said first alloy, at least one said reception zone (5) enveloping one said respective end zone (6) relating to the assembly of the same said solderable foot (40), or at least one said end zone (6) enveloping one said respective reception zone (5) relating to the assembly of the same said solderable foot (40), or at least one pair formed of one said end zone (6) and one said complementary reception zone (5) including, in a first assembled state which is not soldered or brazed, a tapping cooperating with a threading, characterised in that said first alloy is an aluminium alloy, and in that said second alloy is a titanium alloy, or conversely.
2. The one-piece dial assembly (10), whose material is an aluminium and titanium alloy, including a dial (1) according to claim 1, characterised in that, in at least one pair formed of one said end zone (6) and one said complementary reception zone (5), said end zone (6) and said reception zone (5) are non-detachably joined at a soldered or brazed connection between said flange (2) and said concerned solderable foot (40).
3. The one-piece dial assembly (10) according to claim 2, characterised in that, in each pair formed of one said end zone (6) and one said complementary reception zone (5), said end zone (6) and said reception zone (5) are non-detachably joined at a soldered or brazed connection between said flange (2) and said concerned solderable foot (40).
4. The one-piece dial assembly (10) according to claim 2 or 3, characterised in that said dial assembly (10) includes an anodised surface layer, or a chromic or sulphuric anodic oxidation surface layer.
5. A watch (1000) including a dial assembly (10) according to one of claims 2 to 4.

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