AndCavanaugh's meticulous analysis of Patek Philippe's central rotor automatic movements provides an invaluable historical and technical resource for collectors. This deep dive into the evolution of calibers 310, 315, 324, and 26-330 illuminates the brand's continuous pursuit of horological refinement. Understanding these generational shifts is crucial for appreciating the intricate engineering behind some of Patek Philippe's most iconic timepieces.
In the late 70s Patek was juggling four automatic movements: 240, 28-355 (JLC 920), 27-460, and 350. They wanted a thin, automatic movement with sweep seconds that wasn’t the 350. Eventually this movement family, and the 240, would replace the other three and is still going today. Unlike the 240, this movement family has had extensive changes across four generations. There is some bleedover between generations, and differences within generations, so take none of this as gospel.
310 (and 335)1980ishThe 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.
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.
About the Patek Philippe Ref. 5135
The Patek Philippe Reference 5135 represents a masterful interpretation of the annual calendar complication, introduced as part of Patek Philippe s contemporary collection following the brand s pioneering work in accessible perpetual calendar alternatives. This reference showcases Patek Philippe s commitment to horological excellence while maintaining the practical sophistication that defines their modern complicated timepieces. The 5135 carries forward the prestigious legacy of Patek Philippe s calendar watches, offering collectors a refined example of Swiss haute horlogerie that balances technical complexity with everyday wearability.
At the heart of the Reference 5135 beats the automatic Caliber 324 S QA LU, a sophisticated movement that displays the annual calendar function with exceptional precision and reliability. This self-winding caliber incorporates Patek Philippe s advanced gear train technology and maintains the brand s stringent finishing standards throughout its construction. The movement elegantly orchestrates the display of day, date, month, and moon phases, requiring adjustment only once per year at the end of February. The 38.2mm rose gold case provides optimal proportions for this complex movement while ensuring the various calendar indications remain clearly legible on the pristine white dial.
The design philosophy of the 5135 emphasizes classical elegance through its clean white dial presentation, which serves as the perfect canvas for the multiple calendar apertures and subsidiary dials. The fixed bezel and sapphire crystal construction reflect Patek Philippe s commitment to durability and optical clarity, while the overall aesthetic maintains the timeless sophistication expected from Geneva s most prestigious manufacture. For collectors, the Reference 5135 occupies a significant position as an accessible entry point into Patek Philippe s complicated watch segment, offering the prestige of annual calendar functionality in a format that exemplifies the brand s design philosophy and technical mastery.
Specifications
- Caliber
- Cal.324 S QA LU
- Case
- Rose gold
- Diameter
- 38.2mm
- Dial
- white
- Water Resist.
- 30m
- Crystal
- Sapphire
About the Patek Philippe Air King Ref. 5520
The Patek Philippe Reference 5520P-001 Alarm Travel Time represents a significant technical achievement, combining two of the brand's signature complications: the Travel Time dual time zone mechanism and a chiming alarm. This reference is distinguished by its integrated alarm function, which is a rare complication for Patek Philippe and is executed with a hammer and gong system, audible through the case. It stands apart from other Travel Time models by offering this additional functionality in a contemporary platinum case.
The watch features a platinum case with a diameter of 42.2 mm and a thickness of 11.6 mm. It is powered by the self-winding caliber AL 30-660 S C FUS, which incorporates 574 components. This movement provides a power reserve of 48 hours and is visible through a sapphire crystal case back. The dial is presented in an ebony black sunburst finish, complemented by white gold applied numerals with a luminescent coating.
For collectors, the Reference 5520P-001 is notable for its technical complexity and the integration of a chiming alarm, a complication not frequently found in Patek Philippe's modern collection. Its platinum construction and the sophisticated alarm mechanism appeal to those seeking a highly functional and mechanically intricate timepiece. The watch's design maintains a balance between its technical capabilities and a refined aesthetic.
Specifications
- Caliber
- AL 30-660 S C FUS
- Case
- Platinum
- Diameter
- 42.2 mm
- Dial
- Ebony black sunburst
- Water Resist.
- 30 m
- Crystal
- Sapphire
