TicTacTalks ForumPosted by Asi
August 2, 2006 - 11:56AM cet
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Email : asimut@gmail.com
Following Yves' post on the Swiss industry standards it is worthwhile to mention the Geneve Seal. The Society of Watchmakers was formed in 1873 to better formalise the ongoing search for excellence in watch making. The society persuaded Geneva's Grand Council to set up an inspectorate, drawn from the city's Ecole d'Horlogerie, to examine and certify the best mechanical watches. Thus was born the 'Poinçon de Genève' - the Geneva Seal, and today, the Geneva Seal still sets the most demanding standards for watch making anywhere in the world.
The Seal is famous because most Patek watches bear it and it can be seen engraved on the movement.
Vacheron Constantin placed this seal on the dial when they made their amazing Tour de l'Ile (7 pieces, 2005) grand complication watch to celebrate 250 years (The oldest surviving watch company). This watch deserves a seperate post, as it is claimed to be the most complicated wristwatch ever produced.
the criteria as taken from the Patek website:
1a) The workmanship of all the calibre's components, including those of the additional mechanisms, must meet the requirements of the office for optional inspection of Geneva watches.
(1b) Steel parts must have polished angles and their visible surfaces smoothed down. Screw-heads have to be polished, with their slots and rims chamfered.
(2) All movements should be fitted with ruby jewels with polished convex-shaped holes for all train and escape wheel pivots. On the bridge side the jewels should incorporate a polished counter sink. A centre wheel jewel hole in the base plate is not required.
(3) The balance spring should be pinned up in a grooved plate with a stud having a rounded collar and cap. Mobile studs are allowed.
(4) Split or fitted indexes are allowed with a holding system except in extra thin calibres where the holding system is not required.
(5) Regulating systems (balances) with variable radius of gyration are allowed provided they comply with criteria one (A) and one (B).
(6) The wheels of the going-train have to be chamfered above and below and have a polished sink. In wheels 0.15 mm thick or less, a single chamfer is allowed on the bridge side.
(7) In wheel assemblies, the pivot shanks and the faces of the pinion leaves have to be polished.
(8) The escape wheel has to be light, not more than 0.16 mm thick in large Calibres and 0.13 mm in calibres under 18 mm, and its locking-faces have to be polished.
(9) The angle traversed by the lever is to be limited by fixed banking walls to the exclusion of pins or studs.
(10) Movements fitted with shock-proofing are accepted.
(11) The ratchet wheel and the crown wheel should be finished according to registered patterns.
(12) Wire springs are not accepted
Asi
