Patek Philippe

The first generation was caliber 310, a unidirectional (clockwise) automatic movement with indirect sweep seconds and date that was 26 mm in diameter while being only 3.15 mm thick. These movements used an off-the-shelf assortment with a generic balance, Trivolis, Incabloc, flat hairspring, and 4hz beat rate. They did not carry the Geneva seal.

310’s date wheel was flush with the movement, but too broad for the smaller dials of the Nautilus collection. Patek created caliber 335, which uses a narrower date wheel which sits on top of the movement, at the cost of an increased height (3.45 mm). A quickset for the date was added a few years later.




315 (and 330)

1990ish

310’s automatic winding system was unreliable and inefficient. Patek reworked the automatic winding system in its successor caliber, 315, which now winds counterclockwise. Once again there would be a variant with narrower date wheel, the 330. This time Patek graced 315/330 with a gyromax balance, Geneva stud, KIF, and Geneva seal, as well as lowering the beat rate to 21,600 bph.

Unlike its predecessor, 315 would act as a base for complications, including Patek’s retrograde perpetual and annual calendars. The complicated versions would have some features of the next generation. All three generations of complicated movements have the bridge side barrel arbor jeweled. There was also an advanced research version of 315 with silicon escapement and balance spring.




324

2004

For the third generation Patek increased the beat rate to 28,800 with the new 2-spoke-4-weights gyromax balance (these can also be found on later 315s). Eventually on these movements would all get silicon Spiromax hairsprings. The rotor grew 0.1 mm in diameter and 0.08 mm in height, the hand winding system was beefed up, and tooth-profiles for the going and date trains were changed to make power transmission more uniform (per Patek’s press release for the 5135). The dial side bridge is now two separate parts, but I’ve noticed this was already present on complicated 315s. Also they switched back to Incbloc.

Dandong (major movement manufacturer in Liaoning) allegedly makes a 324 “clone” for use in high quality “replica” watches. These copy the basic design of caliber 324, but parts are not interchangeable with genuine ones. I wrote a mini post on Atelier Wen’s use of a sterile version here.




26-330

2019

The winding system was redesigned for a third time. Previously the pinion by the rotor would move laterally, decoupling from the winding train when the rotor turns clockwise, and recouping to wind the barrel when the rotor turns counterclockwise to wind the watch. 26-330 instead uses a pair of pawl wheels (one by the rotor and one by the barrel). This system (and the new rotor shape) was soft launched on the 5520 (cal. 30-660) alarm travel time a few years back. It also uses a new rotor mount which debuted on the cal. 28-520 all the way back in 2006.

Since these movements have indirect seconds they used a friction spring, like you see on chronograph seconds hands. With the fourth generation this was replaced by a special LIGA etched third wheel which grips the sweep seconds pinion. Once again, this has been used for chronograph seconds hands by Rolex and Patek. Also it hacks now. All of these changes are explained well in this video.