En y réfléchissant... (Revues & Essais)

posté par Ed the Grocer (modérateur) , Paris, 13/04/21, 11:08
(Modifié par Ed the Grocer le 13/04/21, 11:31)
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En revenant sur le sujet à tête reposée, j'aimerais bien avoir l'avis de quelqu'un qui aurait réellement examiné ce calibre 30-255, et un exposé du cahier des charges, et de la réalisation.

Parce qu'un nouveau calibre manuel, et de grand diamètre chez Patek, c'est une révolution !

Je ne voudrais pas qu'une stérile recherche d'angle rentrant un peu ayatollesque ne nous (me) détourne du réel intérêt de ce mouvement.

30-255 PS
Small seconds. Diameter: 31mm. Height: 2.55mm. Number of parts: 164. Power reserve: min. 65 hours. Frequency: 28,800 semi-oscillations/hour (4 Hz). Hallmark: Patek Philippe Seal.


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Voici ce qu'en dit SJX

“central pinion without a wheel plate that meshes with the center wheel via an intermediate wheel” – essentially a more streamlined arrangement of the gears – and another are the crown and ratchet wheels that sit under the barrel bridge instead of over.
The manual-winding movement boasts 65 hours of power reserve, a stark improvement over the 44 hours of the cal. 215 PS.

It does that with twin barrels that unwind in parallel, or at the same time. The double, parallel barrels increase the torque of the movement substantially: the balance wheel has the highest moment of inertia amongst its 4 Hz movements according to Patek Philippe. In other words, it has excellent HDF.

This improves the stability of its beat rate – meaning better timekeeping regardless of external factors like shock – and also allows for easier regulation. And like all movements certified with the Patek Philippe Seal, the cal. 30-255 PS is rated to an impressive -3/+2 accuracy per day.

Notably, the cal. 30-255 PS also appears slightly better finished than its predecessors, showing the usual Cotes de Geneve and perlage, but also improved details like the bevels of the bridges that incorporate sharp external angles, albeit accomplished by stamping.

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Ed the Grocer ancienne maison l'Epicier


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