Classifications

• • A—HUMAN NECESSITIES
  • A44—HABERDASHERY; JEWELLERY
  • A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
  • A44C5/00—Bracelets; Wrist-watch straps; Fastenings for bracelets or wrist-watch straps
• • 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
  • G04B37/225—Non-metallic cases
• • 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
  • Y10T29/49579—Watch or clock making
  • Y10T29/49584—Watch or clock making having case, cover, or back
• • 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
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/8305—Miscellaneous [e.g., treated surfaces, etc.]

Definitions

• the present invention relates to a clothing element for a wristwatch, such as a box or a bracelet, at least part of which is made of a composite material.
• the required mechanical properties are in fact only critical on the surface and in particular on surfaces exposed to attacks due to lines and shocks.
• the inclusion of microscopic particles has the effect of modifying the elastic properties of the plastic, especially with respect to stresses such as shear, compression, traction, bending, etc.
• these fillers have a less pronounced effect with respect to the surface hardness due to their microscopic size. Indeed, a sharp element can scratch the surface of such a charged plastic while passing between the particles because of their size. It therefore turns out that effective protection of the surface of a plastic part against rays does not only depend on the hardness of the particles used as filler and on the proportion of these particles.
• too high a proportion of microscopic fillers can have the consequence of making the resin more fragile to impact, which is obviously not desirable in the case of a watch case which notably includes edges capable of being chipped. if the box material is brittle.
• the object of the present invention is to at least partially remedy the aforementioned drawbacks.
• At least part of the clothing element is made of a material which comprises an organic binder and macroscopic particles of mineral substances contained in the binder.
• These particles are exposed on at least a visible surface portion of the element and occupy 60% to 95% of this portion.
• Such an element has the advantage of having excellent protection against lines and shocks in its surface thus formed, due to the macroscopic dimension of the inclusions and their sufficient density, without making the composite excessively fragile. It is thus possible to produce a watch case or a bracelet having inalterability properties close to those of boxes or bracelets covered with sintered carbides or nitrides, by an injection molding process.
• elements produced according to the invention have a new aesthetic appearance, in particular after polishing the surface which brings out the colors of the inclusions different from that of plastic, for example. Indeed, the inclusions of nitrides, oxides, carbides, etc., can have very diverse colors.
• any mineral material can be combined with resin, namely carbides, borides, nitrides, carbonitrides, oxides, etc., but also sintered agglomerates such as TiC bound with Ni, elements with a monocrystalline network such as ⁇ -A1 2 0 3 (corundum) or with an amorphous structure such as glass, particles of stellite or hard steel of the same type as those used for sintering.
• resin namely carbides, borides, nitrides, carbonitrides, oxides, etc.
• sintered agglomerates such as TiC bound with Ni
• elements with a monocrystalline network such as ⁇ -A1 2 0 3 (corundum) or with an amorphous structure such as glass, particles of stellite or hard steel of the same type as those used for sintering.
• the choice of resin is relatively limited.
• a technical plastic is chosen as the resin, in particular an acetal homopolymer resin, such as that sold by Du Pont under the trade name "Delrin” (registered trademark), of the 100 ST type, which has the advantage of having resistance. Izod impact (with notch) of 900 J / m, that is to say 7 to 30 times greater than that of the other "Delrin” which constitute one of the best ranges of technical plastics.
• This material is moldable by hot injection.
• Other materials such as polyamide 12 or polycarbonate can also be used.
• the watch element such as the middle part, the back, or the bezel, or even the back-middle part of a case, or the bracelet is placed in the mold cavity intended for molding the watch element, a charge of mineral particles which can comprise a mixture of the various abovementioned substances, but also consist of only one of these substances, depending on the decorative effect sought.
• the particle size can also be chosen to be uniform or, on the contrary, as diverse as possible.
• the smallest particle size is of the order of 0.1 mm; it can go up to several millimeters. When the particles are of different colors, one can for example choose the size according to the color.
• the proportion of particles in the volume can be variable, but it is generally made so that there is on the surface of the watch element intended to form a visible surface portion, and particularly the parts most exposed to the wear, as large a proportion as possible of mineral inclusions. Then, the mold is closed and the resin is injected under pressure. The element thus produced then has a mosaic structure formed of hard particles and resin which keeps these associated with each other. These particles occupy most of this portion. After cooling and demolding, the surfaces of the molded element intended to form the visible parts from the outside are advantageously polished with a diamond wheel to bring the inclusion particles perfectly flush with the surface of the resin. The latter tends to withdraw during cooling. This grinding also makes it possible to highlight the different colors of the particles which are flush with the surface of the element, since, to promote their anchoring in the resin, they are preferably used in the raw state. These particles can advantageously come from manufacturing waste, but they can also be produced specially.
• the charge of mineral material in the form of particles larger than or equal to 0.1 mm can be incorporated into the resin before its injection into the mold.
• this technique poses abrasion problems when the resin loaded with particles moves in the injection conduits.
• a third technique consists in including the mineral particles only at the surface and in particular on the visible surfaces.
• the resin is injection molded without filler.
• the particles are included as desired on the portions of desired surfaces, in particular the visible surfaces, by heating the particles to a temperature sufficient to locally soften the resin and allow their penetration.
• This technique offers in particular the advantage of being able to control the arrangement of the particles according to their dimensions and / or their colors, with a view to specially protecting certain parts of the surface, in particular the edges and / or creating decorative patterns which do not are not left to chance as in the variants described above.
• the portion of the visible surface and therefore exposed to attack of all kinds, covered by hard particles must be greater than the half the surface.
• it will be between 60% and 95%, and preferably around 85%.
• the hardness of the particles will generally be chosen at 1400 Hv. Some of the particles may even be made of transparent substances depending on the desired aesthetic appearance.
• the organic binder and the macroscopic particles have a very high wettability in order to ensure maximum fluidity of the binder and perfect anchoring of the particles.
• Processes are known in which particular elements are added to the organic binder to make it wetting.
• the particles they will be made wetting by a thorough cleaning which will rid them of all fats or other impurities.
• this treatment will prevent accidental formation of bubbles which could give rise to tears.
• the binder is an adhesive ensuring adhesion between the particles.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Adornments (AREA)
• Powder Metallurgy (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Physical Vapour Deposition (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=4254750

Family Applications (1)

Country Status (8)

Families Citing this family (3)

Family Cites Families (6)

• 1984
  • 1984-07-12 CH CH338284A patent/CH658160GA3/fr unknown
• 1985
  • 1985-07-02 KR KR1019850004746A patent/KR880000223B1/ko not_active IP Right Cessation
  • 1985-07-08 EP EP19850108437 patent/EP0168009B1/fr not_active Expired
  • 1985-07-08 AT AT85108437T patent/ATE34470T1/de not_active IP Right Cessation
  • 1985-07-08 DE DE8585108437T patent/DE3562829D1/de not_active Expired
  • 1985-07-11 JP JP60151466A patent/JPS6157633A/ja active Pending
• 1987
  • 1987-01-08 US US07/004,788 patent/US4730288A/en not_active Expired - Fee Related
• 1990
  • 1990-07-26 HK HK56090A patent/HK56090A/xx unknown

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