Lot 118

Patek Philippe

Amagnetic

A very fine and extremely rare vintage Geneva wristwatch with individual case according to Swiss patent "Brevet 340786" with special locking device system for a quick change between steel and leather strap - sold on April 13th, 1962 - with Patek Philippe extract from the archives

Sold

On the cylindrical part of the case is a fine thread and the ring nut next to it. At the end of this thread is a shoulder, which has inserts for the mobile lugs at 6 and 12. The mobile lugs are then pressed into these and fixed in place with the subsequently screwed-on ring nut. This construction made it possible to replace the leather strap with a metal strap whose lugs were identical in shape to those of the leather strap.
The calibre 27-AM400 was developed for watches that had to withstand the danger of magnetic fields. The Gyromax balance and Breguet hairspring were used, with the balance, lever and other components made of anti-magnetic material.
This watch is illustrated and described in: J. Michael Mehltretter "Die Noblen aus der Schweiz", Ulm 2006, p. 148 and in J. Michael Mehltretter "Armbanduhren, Technik, Funktion und Bewertung", 2nd corrected edition, Stuttgart 2022, p. 187f.