====== PP 27-460 ======
Calibre **27-460** is an [[automatic]] watch movement from [[Patek Philippe]].

This was the successor to Patek Philippe's first automatic movement, produced from [[1960]] through [[1985]].

===== Info =====
[[PP 12-600 AT|Calibre 12-600 AT]] was introduced by Patek Philippe in [[1953]] and became a classic, loved by watch enthusiasts today. Its successor, [[1960]]'s Cal. 27-460, was an evolution of that famous movement and lasted in production until [[1985]], though the company had introduced many other movements in the intervening 25 years. Walt Odets called Cal. 27-460 "the reigning queen of that half century" and "the most elaborate and costly simple automatic watch movement ever produced."

The name of Cal. 27-460 explains its key features 

  * The movement was 27 mm (12 [[ligne]]) in diameter
  * The movement was 4.60 mm thick

Like Cal. 12-600 AT, this movement features a solid 18 karat yellow gold rotor, consummately decorated with [[engine turned|engine turning]] even though no watch at the time had an [[exhibition case back]]. Timing was kept using Patek Philippe's patented [[Gyromax]] balance wheel, and this wheel beats at 19,800 A/h. Aiding the Gyromax wheel is an adjustable balance spring stud carier, replacing the [[swan neck regulator]] in the predecessor, and self-compensating [[Breguet balance spring]]. The other main change from Cal. 12-600 AT is a revamped rotor ball bearing, a source of trouble due to the massive rotor.

The design calls to mind Patek Philippe's mid-century hand-winding movements. Separate [[cock]]s are used for the balance wheel, escape wheel, and fourth wheel. A large bridge is used for the third wheel and center wheel and also acts as a mounting point for the rotor bearing. The movement is rhodium plated and finished to the standards of the [[Geneva Seal]]. Cal. 27-460 lasted in production for 25 years, powering most of Patek Philippe's high-end watches and [[complications]]. It was finally retired in [[1985]], a remarkably long run for a 1950's design, and replaced by the [[micro-rotor]] [[PP 240|Cal. 240]].

===== Complications =====
  * Cal. 27-460 - The basic movement, introduced in [[1960]], and 4.6 mm thick
  * Cal. 27-460 M - With date, introduced in [[1961]], and 5.35 mm thick

===== See also =====
  * [[PP 12-600 AT]] the predecessor
  * [[PP 240]] the successor

===== External Links =====
  * [[http://www.timezone.com/2002/09/16/la-grande-dame-des-automatiques-suisse-the-patek-caliber-27-460/|La Grande Dame des Automatiques Suisse: The Patek Caliber 27-460]]


<WRAP ud ud_mov>

**Manufacturer:**
  * [[Patek Philippe]]

**Description:**
  * [[Automatic]] movement

**Functions:**
  * Hour/minute hands
  * [[Small seconds]]
  * Date

**Data:**
  * 19,800 A/h
  * 12 [[ligne]] (27 mm) wide, 4.6 or 5.35 mm high
  * 30 jewels

**Production period:**
  * [[1960]]-[[1985]]
</WRAP>

{{tag>Movements Automatic_movements Patek_Philippe_calibres}}