Classifications

• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B37/00—Cases
  • G04B37/22—Materials or processes of manufacturing pocket watch or wrist watch cases
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/06—Alloys based on copper with nickel or cobalt as the next major constituent
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/4998—Combined manufacture including applying or shaping of fluent material
  • Y10T29/49982—Coating
  • Y10T29/49986—Subsequent to metal working

Definitions

• the present invention relates to a method of manufacturing a watch case made of a material comprising by weight at least 95% copper.
• a watch case carrying such a large percentage of copper has already been proposed in document CH-A-543 764.
• the process for manufacturing components of a watch case is characterized by the fact that a cupro-beryllium alloy suitable for structural hardening by heat treatment is used, machines said elements, then deposits a layer of stainless metallic material on the outside.
• the cupro-beryllium alloy comprises at least 1.8% and at most 2.05% of beryllium and that the heat treatment allowing a structural hardening is an income taking place at 320 ° for at least two hours. .
• the proposed method also makes it possible to obtain by known and proven means, such as stamping, turning, threading, drilling, milling as well as machining, using diamond tools and by a simple heat treatment, a resistant watch case of which all the constituent elements can receive a hard surface treatment, allowing the watch to keep intact, for a practically unlimited time, even if it is worn under very severe conditions, an aspect aesthetic and practically unalterable.
• Beryllium, alloyed with copper or bronze finds its application in electricity where it has been widely used as electrical spring contacts. However, it has a serious disadvantage which is that of being toxic. Beryllium and its salts should be handled with the utmost care. They should not be touched to check the softness effect they present. It is therefore necessary to observe a certain work discipline, when you know that a concentration in the air exceeding two milligrams per cubic meter is dangerous. These reasons mean that beryllium and its alloys are currently difficult to supply, as is also difficult the problem posed by the reprocessing of waste.
• Document SU 154 669 describes an electrically conductive alloy based on at least 95% copper, the rest comprising, among other things, cadmium. We know that cadmium is toxic and must be avoided at all costs.
• the method of manufacturing the watch case according to the invention implements the steps which appear in claim 1.
• the holder of the present invention used a material used, to his knowledge, in the electrical industry only, as conductors or elastic contacts.
• a material used to his knowledge, in the electrical industry only, as conductors or elastic contacts.
• at least one of the constituent parts of the watch case is made of a material comprising at least 95% by weight of copper, the rest being composed of elements capable of increasing the mechanical resistance of the copper excluding the beryllium and cadmium.
• this material is covered with a layer used to protect and decorate the box.
• the following composition has excellent results and can constitute a preferred composition: Copper: 98.2%, nickel: 1%, lead: 0.55% and phosphorus: 0.22%.
• Copper 98.2%
• nickel 1%
• lead 0.55%
• phosphorus 0.22%.
• the remaining elements are not limited to nickel, lead and phosphorus but may include, for example, manganese or tin.
• the indicated material can be used to make the only middle part of the box, this middle part can include an integrated or attached bezel.
• the middle may also carry horns used to attach the bracelet to the box. Shoulder and horns can then be made in one piece with the indicated material. It goes without saying that the bottom of the box can also be made of the same material.
• the procedure according to the invention is as follows: We start by providing the material described above, this material comprising at least 95% copper, the rest being composed of elements capable of increasing the resistance of the copper excluding beryllium and cadmium. This material can be presented in a strip to facilitate mass production.
• the preferred composition indicated above can be chosen for the excellent results which it exhibits.
• the material is then cold deformed in a single operation.
• This deformation is carried out by means of a tool capable of both cutting and then stamping the material chosen to give the box its final shape which can be that of its middle with its horns.
• Cold deformation in a single operation is very advantageous because of the saving in tools and time that it presents.
• the material or at least the surface areas of this material, will be work hardened during the stamping or stamping operation of the material, which will contribute to hardening it and therefore making it mechanically more resistant.
• the presence of elements such as nickel for example also makes it possible to thermally harden the material and this between the cold deformation operation and the covering operation.
• the product obtained is introduced into an oven heated to about 400 °.
• the part thus obtained has an unattractive reddish appearance and not very resistant to corrosion. We will therefore coat it with a layer used to decorate and protect it.
• This coating can be done in various ways, for example by galvanic means or by physical vapor deposition (PVD). Chromium, nickel or even gold can be deposited by galvanic means, this deposit being facilitated by the fact that the substrate is made of copper.
• PVD physical vapor deposition
• electrochemical or electrolytic polishing can be carried out.
• This type of polishing impossible with brass, advantageously replaces the mechanical polishing commonly used but expensive in time.
• the PVD deposition on copper alloys calls for an important comment here. It will be noted first of all that the copper alloy most used to make a watch case is brass. Brass contains a large percentage of zinc which makes it unsuitable for receiving a protective layer via PVD. Indeed, the PVD deposition being done under vacuum (between 10 ⁇ 2 and 10 ⁇ 4 mbar) and at a relatively high temperature (between 200 and 400 ° C), the zinc becomes volatile and evaporates during the treatment and that of fact that its vapor pressure is not negligible under the above conditions. This evaporation leads to an irregular deposit and little resistant of the layer you want to apply and finally an unacceptable appearance for the finished part.
• the deposition by PVD process has yet another advantage which is that of economizing on the thermal hardening operation, this hardening taking place at the same time as the deposition since the deposition temperature (between 200 and 400 ° C.) found to be substantially the same as the curing temperature.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Physics & Mathematics (AREA)
• Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Laminated Bodies (AREA)
• Physical Vapour Deposition (AREA)
• Adornments (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=4281529

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Family Cites Families (8)

• 1988
  • 1988-12-21 CH CH4731/88A patent/CH674293B5/fr unknown
• 1989
  • 1989-12-11 DE DE8989122807T patent/DE68901453D1/de not_active Expired - Lifetime
  • 1989-12-11 EP EP89122807A patent/EP0374669B1/fr not_active Expired - Lifetime
  • 1989-12-12 CA CA002005218A patent/CA2005218A1/en not_active Abandoned
  • 1989-12-19 JP JP1327480A patent/JPH02221359A/ja active Pending
  • 1989-12-20 US US07/453,929 patent/US5021101A/en not_active Expired - Fee Related
  • 1989-12-21 CN CN89105844.3A patent/CN1043804A/zh active Pending
• 1992
  • 1992-11-26 GR GR920401795T patent/GR3006335T3/el unknown

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