Patek Philippe Ref. 3970 First Series Perpetual Calendar Chronograph

Technical characteristics

Type

Chronograph

Casemaker

Ateliers Réunis

Case Number

2’824’111

Case Material

18K yellow gold

Place recorded

Switzerland

Case Dimensions

36mm diameter

Movement Calibre

Manual, cal. CH 27-70 Q, 24 jewels

Maker / attribution

Patek Philippe

Design

Visible features

• Silver dial with dual apertures for day and month below 12 o'clock. • Three subsidiary dials at 3, 6, and 9 o'clock displaying 30-minute register with leap-year cycle, date with moon phase aperture, and running seconds with 24-hour indication. • 18K yellow gold case with stepped bezel, fluted crown bearing the Calatrava cross, round pump pushers, and case-flank correction pushers. • Fitted to a tan grained leather strap with matching contrast stitching.

Dial Configuration and Functions

Direct visual inspection shows a silver dial with applied yellow gold rectangular indices, feuille hands, and dual apertures below 12 o'clock displaying the day and month. The dial outer perimeter incorporates printed minute/second graduations. Three subsidiary dials are positioned at 3, 6, and 9 o'clock: a 30-minute chronograph register with an integrated leap-year indicator at 3 o'clock, a date ring enclosing a moon phase aperture at 6 o'clock, and running seconds paired with a 24-hour display at 9 o'clock. The cataloguing essay notes these subsidiary dials are slightly darker than the silver dial plate.

Movement Details and Archival Documentation

The lot details record the movement as the manual-wind calibre CH 27-70 Q with 24 jewels, catalogued under movement number 875’004 and case number 2’824’111. Because internal mechanism photographs are not provided, mechanical details and markings rest on the seller's cataloguing. The watch is reported to be accompanied by a Patek Philippe Certificate of Origin dated 31 January 1987, a fitted presentation box with outer packaging, and an Extract from the Archives confirming manufacture in 1986 and sale on 3 February 1987. The cataloguing also specifies an 18K yellow gold Patek Philippe pin buckle fitted to the leather strap.

Series Identification and Case Construction

This Patek Philippe reference 3970 is documented by the auction house as a first-series perpetual calendar chronograph in an 18K yellow gold 36mm case. According to the cataloguing essay, the first series was produced between 1986 and 1988 exclusively in yellow gold, beginning with movement number 875’000 with approximately 100 examples produced. Bearing movement number 875’004, this piece is described by the cataloguer as the fifth example made in the series. The yellow gold case displays stepped lugs, round pump pushers, and case-flank correction pushers. The auction cataloguing reports a snap-on case back bearing the casemaker key number 28 stamped on the inside, which the cataloguer attributes to casemaker Ateliers Réunis. Direct visual confirmation of the movement and internal case-back hallmarks is not possible from the provided single front-facing photograph.

Identification

Reference

3970

Serial number

875’004

Source note

Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.

Catalogue references

No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.