Classifications

• • G—PHYSICS
  • G04—HOROLOGY
  • G04D—APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES
  • G04D5/00—Oiling devices; Special lubricant containers for watchmakers

Definitions

• the present invention relates to a method of lubricating a timepiece movement, more particularly its escapement.
• the lubrication of the escapement of a timepiece is a problem for which an absolutely satisfactory solution has not yet been found.
• the generally used method consists in depositing by means of an oil-pike a drop of a suitable oil used in watchmaking on the impulse faces of the pallets of the lever. Owing to the successive passages of the teeth of the escape wheel, the drops of oil deposited on the pallets are swept, so that the major portion of the oil is carried outside the functional surfaces, where it can no longer take a part in the lubrication.
• the present invention aims at overcoming the several above-mentioned drawbacks. It has just been mentioned that the application of a solid lubricant gives good results in the watch.
• the lubricating method of the invention aims at increasing the adherence of a solid lubricant on the base material in such a manner that the lubricating layer cannot be destroyed by the conventional cleaning processes used in watchmaking.
• the present invention is based upon the property of certain solid lubricants of strongly adhering to the surface onto which they are applied, inasmuch as the application is made under a 3,511,340 Patented May 12, 1970 strong pressure and the finish of the surface is such that it promotes a catching of the lubricant.
• the lubricating method of the invention comprises the steps of treating the surface of the pieces so as to give them a rugosity lying between .1 and 1,u, and then treating the pieces, brought into this state, into a centrifugal barrel the acceleration of which lies between 1 and 20g and in which are contained, besides the pieces' -to be treated, a solid lubricant in powder form, a carrying mass for the latter and a granulated mass adapted to produce a pressure for fixing the solid lubricant onto the pieces to be treated.
• this surface may be subjected to different types of preparations. It is possible to give to the surface, by a mechanical process, a suitable rugosity, which may be obtained by a grinding, polishing, sanding or any other similar operation. Another process of preparing the surfaces may consist of 'a chemical or galvanic treatment. Among the former, let us cite, for instance, the phosphatation. It is also possible, in order to obtain the desired surface finish, to perform a chemical attack of the surface; in the case of pieces of brass, for instance, the desired rugosity may be obtained by an attack with an acid such as nitric acid or any other bath having the same action.
• a galvanic process is preferably used.
• the piece to be treated being made of steel, a first deposit of gold of normal constitution is effected.
• This deposit serves for promoting the adherence of the next deposit of gold which is effected in such conditiousby reducing the contents of free cyanide of the bath and by adapting the current intensity-that it presents a porous constitution and a rough surface.
• the thus obtained rugosity is easily adjustable by choosing the conditions of the galvanic deposition.
• a gold deposit is preferably effected, since its coefficient of friction with respect to ruby is favourable, but it is also possible to use other metals such as rhodium, silver or alloys such as lead-tin or nickel-tin alloys.
• the rugosity of the surface is adapted in such a manner that the geometry of the piece is not altered and the tolerances of manufacture are respected.
• the rugosity of the piece must lie between .1 and 1 (maximum height of the asperities) and its mean quadratic deviation preferably lies between .06 and .7,u..
• the mean quadratic deviation is, as is wellknown, the square root of the arithmetic average of the squares of the deviations.
• a centrifugal barrel After the pieces have received the desired surface preparation, they are put in a centrifugal barrel.
• the latter is loaded with a mixture of a solid lubricant in powder form (e.g. molybdenum disulfide, graphite or tungsten diselenide), of a carrying mass for the latter (consisting for instance of a plastic material or simply of sawdust) and of a granulated mass, preferably metallic, acting as a charge and serving for producing, when the centrifugal barrel is running, a pressure sufiicient for causing the lubricant to penetrate into the surface of the piece and strongly adhere thereto.
• the said granulated mass may consist for instance of balls of lead or steel, having a diameter of l-2 mm.
• the pieces in the centrifugal barrel After the passage of the pieces in the centrifugal barrel, they may be dipped in a final bath and then dried.
• the final bath comprises, for example, 12% of oil used in watchmaking in dissolution in a solvent such as Freon or benzine.
• a solvent such as Freon or benzine.
• the latter treatment still improves the lubrication.
• Pieces of escapement treated in the described conditions have shown, upon tests made in laboratories, an excellent resistance to the action of the cleaning baths, as well as an excellent behaviour in the watch.
• the invention really brings a solution to the problem, up to now not satisfactorily solved, of the lubrication of the escapement.
• Other friction pieces of the watch, treated by this method have also shown a most favorable behaviour, entirely competitive on the technical point of view with the conventional methods, with the additional advantage of a lubrication of greater duration.
• a method of lubricating a timepiece movement, more particularly its escapement characterized by treating the surface of the pieces so as to give them a rugosity lying between .1 and 1,11, and then treating the pieces, brought into this state, into a centrifugal barrel the acceleration of which lies between 1 and 20g and in which are contained, besides the pieces to be treated, a solid lubricant in powder form, a carrying mass for the latter and a granulated mass adapted to produce a pressure for fixing the solid lubricant onto the pieces to be treated.
• a method according to claim 1 characterized by treating the surface of the pieces so as to give them a rugosity the mean quadratic deviation of which lies between .06 and .7,u.
• a method according to claim 1 characterized in that the desired rugosity of the surface of the pieces is obtained by subjecting said surface to a galvanic treatment,
• the adherence to the base metal being obtained by a first deposit effected in normal conditions, followed by a second deposit effected in modified conditions so that this second deposit has a porous constitution and a rough surface.
• a method according to claim 1 characterized by using sawdust as a carrying mass for the lubricant.
• a method according to claim 1 characterized by using metallic balls as a granulated mass.
• a method according to claim 1 characterized in that, after the passage of the pieces in the centrifugal barrel, the pieces are dipped in a final bath and then dried, said bath comprising a little oil used in Watchmaking in dissolution in a solvent.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Lubricants (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4423875

Family Applications (1)

Country Status (4)

Cited By (5)

Families Citing this family (1)

Citations (4)

• 1967
  • 1967-12-09 CH CH1724367D patent/CH1724367A4/xx unknown
  • 1967-12-09 CH CH1724367A patent/CH493880A/fr not_active IP Right Cessation
• 1968
  • 1968-11-13 DE DE19681808687 patent/DE1808687A1/de active Pending
  • 1968-11-20 US US777455A patent/US3511340A/en not_active Expired - Lifetime
  • 1968-11-22 GB GB55431/68A patent/GB1213836A/en not_active Expired

Patent Citations (5)

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