Press Release
Baselworld 2012
Patek Philippe, Geneva
March 2012

Patek Philippe Ref. 5204
Split-seconds chronograph with perpetual calendar
The circle of classic Patek Philippe chronographs closes
Traditionally, Patek Philippe's classic chronographs can be assigned to one of three categories: simple
chronographs, simple chronographs with perpetual calendars, and split-seconds chronographs withperpetual calendars. This tradition has been upheld with the CH 29-535 PS proprietary caliber that was
launched in 2009 in a basic configuration that would later allow the addition of a calendar module and a
split-seconds mechanism. The Ref. 5170 presented in 2010 and the Ref. 5270 introduced in 2011 are now
joined by the new Patek Philippe split-seconds chronograph Ref. 5204 with an all-new caliber developed
in-house: the CHR 29-535 PS Q.
Two years ago, connoisseurs and collectors already began to speculate that Patek Philippe's coveted Ref.
5004 split-seconds chronograph in a classic manually wound design with a column wheel and a horizontal
clutch, as well as a perpetual calendar, would some day be superseded by a new split-seconds chronographbased on the manufacture’s proprietary CH 29-535 PS caliber. But even experts were surprised how quickly
the suite of in-house chronograph versions was completed. The intention behind the annual flow was topresent a complete line of chronograph models based on the new proprietary movement as soon as
possible, an initiative that yet again demonstrates the competence of the independent, family-owned
manufacture. The ambitious project has now been completed.
Straight from the source: eight in-house chronograph movements in record time.
For decades, Patek Philippe’s emphasis has been on crafting its movements in-house and endowing themwith the manufacture’s inimitable signature. But for a long time, there was an exception to this rule:
Until the CH 29-535 PS chronograph caliber was launched, Patek Philippe classic chronographs werepowered by the 27-70 caliber. It was outsourced from Nouvelle Lémania but in a modified version built tothe manufacture’s specifications and crafted exclusively for Patek Philippe. The caliber was always
assembled and completed in Geneva, and in the opinion of many aficionados, it was the world's best andmost beautiful chronograph movement.
This was the benchmark to be eclipsed in the new millennium with the launch of a unique chronographinitiative that subsequently culminated in 2005 with the development of the CHR 27-525 PS, the world's
thinnest, split-seconds chronograph; in 2006, with the self-winding CH 28-520 IRM QA 24H chronographcaliber with an Annual Calendar; and in 2009, with the manually wound, column-wheel-controlled
CH 29-535 PS chronograph with a horizontal clutch. The mission was accomplished, as evidenced by theapplause from every corner of the horological world. This paved the way for enriching the classic

Chemin du Pont-du-Centenaire 141 – CH-1228 Plan-les-Ouates
Mail address: P.O. Box 2654 – CH-1211 Geneva 2
Tel. +41 22 884 20 20 – Fax +41 22 884 25 47 – www.patek.com

Continued 2chronograph series with different degrees of complexity based on proprietary calibers. Together with thethree Patek Philippe basic chronograph calibers and the chronograph module for the Triple Complication
Ref. 5208, eight chronograph movements were launched in merely seven years.
These eight chronograph calibers belong to the current portfolio of over 50 movements developed andcrafted in-house. It includes 17 basic calibers for wristwatches with a broad repertoire of simple manually
wound and self-winding movements, calibers with tourbillons, perpetual calendars, the Annual Calendar,
minute repeaters, and astronomical functions, etc.
Ref. 5204: Innovation rooted in tradition
The new Patek Philippe split-seconds chronograph with perpetual calendar features all the traditional assetsthat impress true connoisseurs – manual winding, two column wheels, horizontal clutch – yet it is also themost modern representative of its category. This is due on the one hand to the CH 29-535 PS basic caliber
whose six patented innovations are summarized in Annex 2, and on the other, to the perpetual calendar
presented to the world in 2011 with the launch of the Ref. 5270. Accordingly, the new CHR 29-535 PS Q
split-seconds chronograph caliber also beats at a frequency of 28,800 vps (4 Hz), features an instantaneous
30-minute counter and a continuous seconds subdial, and has a power reserve of 65 hours. But the splitseconds mechanism was totally reworked and updated with two technical innovations: an innovative isolator
for the split-seconds lever and the patent-pending mechanism that optimizes the congruent alignment of
the split-seconds hand and the chronograph hand.

Continued 3

1. Isolator for the split-seconds lever
The isolator for the split-seconds lever uncouples the split-seconds wheel from the chronograph wheel assoon as the split-seconds hand is stopped to display a lap time. Because this interrupts the contact between
the split-seconds lever and its heart cam, the stopped split-seconds wheel cannot influence the amplitudeof the balance.
Innovative isolator system for the Ref. 5204P(see Annex 1)

Isolator system in the Ref. 5004

C

O

C

F

P

I
I

A

The isolator for the split-seconds lever relies on an isolator wheelthat is driven by an octopus wheel (O) (isolator wheel / splitseconds spring wheel) on the split-seconds column wheel anduncouples the split-seconds lever as soon as the split-seconds
clamp (C) closes. Because the octopus wheel consistently
rotates in the same direction, it always has to be returned to its
home position together with the split-seconds lever; this is doneby the isolator wheel spring as soon as the split-seconds clamp
opens again.

The unique Patek Philippe design is based on an isolator (A)controlled by the split-seconds column wheel (B). As soon as the
split-seconds clamp (C) closes, the beak (P) of the isolator falls
between two columns and with its teeth advances isolator wheel(D) that uncouples split-seconds lever (E). When the splitseconds clamp is opened again, the beak (P) of the isolator islifted onto a column; its teeth turn the isolator wheel in the
opposite direction and the split-seconds lever is released again.
The swan’s neck cap of the column wheel doubles as a spring (F)that constantly presses the isolator (A) against the split-seconds
column wheel.

Disadvantages:
The disadvantage of this design is the extra height needed by
the isolator wheel spring that sits on the split-seconds wheel (I).
Because the springs of the split-seconds lever and isolator wheel
act in opposite directions, the isolator wheel spring must also
overcome the force of the split-seconds lever spring to rotate
the unidirectional isolator (octopus) wheel back to its home
position.

Advantages:
The new design is thinner because it eliminates the need for an
isolator wheel spring mounted on the split-seconds wheel (I).
The isolator spring is part of the split-seconds column wheel
cap. Unlike the mechanism in the Ref. 5004 in which the isolator(octopus) wheel rotates only in one direction, this isolator moves
back and forth when the split-seconds clamp is opened andclosed. This improves reliability.

Continued 4

The polished column-wheel cap is a venerable Patek Philippe tradition. In the new CH 29-535 PS basic
chronograph caliber, the column-wheel cap handles the extra function of an eccentric that allows
incomparably finer adjustments. With the integrated swan’s neck that serves as an isolator spring, the capon the split-seconds column wheel has now been given an additional function as well.
2. Mechanism for reducing the offset between the split-seconds and chronograph hands
Split-seconds chronographs have two sweep hands: the chronograph hand (trotteuse) and the split-seconds(rattrapante) hand. The split-seconds wheel with the split-seconds hand rotates together with thechronograph wheel to which the chronograph hand is attached; both wheels are connected with the splitseconds heart cam that is mounted on the chronograph wheel. As is the case in all mechanical connections,the ruby roller of the split-seconds lever requires a minimal amount of play to function flawlessly. However,this play can also result in slight deviations of the position of the split-seconds hand when both hands
should be precisely superposed. As a rule, this is concealed by making the chronograph hand slightly wider.
As such, this would not be a serious shortcoming, but then again, it is at odds with Patek Philippe's quest
for perfection. For this reason, the workshops' caliber engineers developed an innovative solution for whicha patent application has been filed.

Ref. 5204
CHR 29-535 PS Q
New split-seconds lever(patent application CH 15991)

Ref. 5004
CHR 27-70
Split-seconds lever

K
M

N

E

When the split-seconds hand is stopped to display a lap time, the contact between the split-seconds wheel
and the split-seconds heart is interrupted because the split-seconds lever is isolated (see isolator). As soon
as the split-seconds hand rejoins the chronograph hand, the ruby roller (M) of the split-seconds lever (E) rolls
along the contour of the split-seconds heart cam (K) until it slips into a recess that defines the congruent
position of the chronograph and split-seconds hands. Because of the mechanical play and movable rubyroller, this position may vary slightly and result in minimal superposition offsets. In the new Patek Philippe
solution, the spring-loaded split-seconds lever has two flat contact surfaces (N) on either side of the ruby

Continued 5roller and the recess of the split-seconds heart cam has two flat shoulder zones. As soon as the ruby roller
drops into the recess, the flat contact surfaces of the split-seconds lever come to rest against the flatshoulders of the split-seconds heart cam. For this reason, the alignment of the split-seconds hand is definedby the stable contact surfaces (N) and no longer by the movable ruby roller. This solution improves the
positional congruence of the split-seconds wheel relative to the chronograph wheel by 75%. The result isthe highly enhanced superposition of the split-seconds hand and the chronograph hand when thechronograph is in the start position or when the split-seconds clamp is released.
The new split-seconds isolator mechanism consists of 42 parts and with a height of 1.7 mm, it is 0.16 mm
thinner than the isolator ensemble of the Ref. 5004. The height of the new Ref. 5204 movement is 8.70 mm
compared with 8.86 mm for the movement of the Ref. 5004.
A calendar for eternity
The perpetual calendar mechanism of the new classic Patek Philippe split-seconds chronograph waspresented in 2011 with the debut of Ref. 5270. It is composed of 182 individual parts and occupies
1.65 mm of the overall movement height of 8.70 mm. This testifies to the manufacture's competence indealing with complex components such as large levers, date wheels, day and month stars, leap-year cams,
lever springs, and other intricate parts. In Patek Philippe timepieces, the appeal of such components lies
not only in the precision with which they were crafted but also in the lavish finishing work invested in them,such as gently concaved and polished chamfers, manually satin-finished flanks, and straight-grained
surfaces. The steel wheels and pinions are also meticulously finished: all teeth and leaves are individuallypolished by hand using a rotating hardwood disk. This work is done not just for the sake of beauty. Smoothly
polished surfaces generate less friction, reduce wear, and transmit kinetic energy more efficiently.
Complexity within, order and clarity on the dial.
Despite the complexity of the elaborate going train, the split-seconds chronograph, and the perpetualcalendar, the well-organized dial presents the twelve separate indications with exemplary clarity andlegibility. It features the typical face of classic Patek Philippe calendar chronographs as did the Ref. 5270,
only this time with the addition of a split-seconds hand. True to tradition, the day of the week and the month
are displayed in two in-line apertures beneath 12 o'clock. The analog date dial at 6 o'clock incorporates themoon phase display. The continuous subsidiary seconds and the jumping 30-minute chronograph counterare located at 9 and 3 o'clock, respectively, in dials whose centers are shifted slightly below the horizontal
centerline of the main dial. This layout is a typical design feature of the movement. The small round aperture
between 4 and 5 o'clock indicates the leap-year cycle, and a second one between 7 and 8 o'clock
accommodates the day/night indicator that simplifies corrections of the calendar functions. The silvery
opaline dial is crafted from 18K gold; it has twelve applied baton hour markers in white gold withluminescent fillings. Together with the black-oxidized gold hour and minute hands, also with Superluminova
fillings, the markers assure outstanding legibility in the dark. The intelligently configured dial sets the stage
for one of the most popular and useful functions of a grand complication wristwatch.
A stylish platinum case for the top model
As the apotheosis of Patek Philippe's classic chronograph trilogy, the new Ref. 5204 is housed in a platinum
case with a diameter of 40 mm and a height of 14.19 mm. The sleek, round, three-part case with straightlugs has a cambered crystal secured in a concave bezel; the sapphire-crystal display back can be replacedwith a solid-platinum case back that is delivered with the watch. Because it is exceptionally tough andContinued 6

difficult to machine, platinum always challenges the skills of casemakers, imposing considerably more stresson the tooling than other classic case materials such as gold and steel. But in return for the hard work
involved, it stands out with an incomparably cool silvery gloss and a physical mass that underscores the classof this timepiece in a very palpable way. As with all of the manufacture's platinum watches, the case ismarked with a flawless Top Wesselton diamond discreetly set between the lugs at 6 o'clock, where it isnoticed only by the wearer. The round start and stop pushers at 2 and 4 o'clock, and of course the pusher
in the crown that controls the split-seconds hand, distinguish this model from simple chronographs withperpetual calendars. The new Ref. 5204 split-seconds chronograph with perpetual calendar is crafted withall meticulous attention to detail mandated by the directives of the Patek Philippe Seal. It is worn on a handstitched, matt black alligator strap with square scales, and secured with a very comfortable and convenientplatinum fold-over clasp.

For further information, please contact:
Jasmina Steele
International Communication and Public Relations Director
Patek Philippe Genève
P.O. Box 2654
1211 Geneva 2
Switzerland
Tel. +41 22 884 20 20
Fax +41 22 884 25 47
Or visit: www.patek.com

Continued 7

Technical data
Grand Complication Ref. 5204 in 950 platinum
Split-seconds chronograph with perpetual calendar
Movement:

Caliber CHR 29-535 PS Q
Manually wound mechanical movement, split-seconds chronographwith two column wheels, chronograph and split-seconds hands,
jumping 30-minute counter and subsidiary seconds. Perpetualcalendar with day, month, leap-year cycle and day/night indicationin apertures, analog date. Moon phases.

Diameter:Height:

32 mm
8.70 mm (of which 1.65 for the perpetual calendar, 1.7 mm for the
split-seconds mechanism)
496 (of which 182 for the perpetual calendar and 42 for the
split-seconds mechanism with isolator)
34
65 hours
Gyromax®
28,800 semi-oscillations/hour (4 Hz)
BreguetNumber of parts:
Number of jewels:
Power reserve:
Balance:Frequency:
Balance spring:
Functions:Two-position crown– Pushed in: To wind the watch– Pulled out: To set the time and stop the seconds hand

Displays:

Center hour and minute hands
Chronograph hand and split-seconds hand from the center
Subsidiary dials:– 30-minute counter between 3 and 4 o'clock– Subsidiary seconds between 8 and 9 o'clock– Date at 6 o'clock
Apertures:– Day and month on an axis beneath 12 o'clock– Moon phase at 6 o’clock– Day/night indication between 7 and 8 o'clock– Leap year cycle between 4 and 5 o'clock
Corrector push pieces:– Day corrector between 10 and 11 o'clock– Month corrector between 12 and 1 o'clock– Moon-phase corrector between 6 and 7 o'clock– Date corrector between 11 and 12 o'clock
Delivered with correction stylus in ebony and 18K white gold

Continued 8

Chronograph pushers:– Start and stop at 2 o'clock– Split-seconds pusher in the crown– Reset at 4 o'clock

Hallmark

Patek Philippe Seal

FeaturesCase:

950 platinum, sapphire crystal, display back with sapphire-crystal
window and interchangeable solid-platinum back, Top Wesselton
diamond in the case at 6 o'clock
Water-resistant to 30 meters

Case dimensions:

Diameter: 40 mm
Height: 14.19 mm
Width between lugs: 21 mm

Dial:

18K gold, silvery opalescentTwelve applied hour markers in black-oxidized gold
“Dauphine” hour and minute hands in black-oxidized gold
Counterbalanced sweep chronograph and split-seconds hands inblack-oxidized steel
Subsidiary dials, off-center, circular guilloché pattern:– Subsidiary seconds between 8 and 9 o'clock: leaf-shaped handsin black-oxidized gold
– 30-minute counter between 3 and 4 o'clock: leaf-shaped handsin black-oxidized gold

Strap:

Alligator leather with square scales, hand-stitched, matt black,fold-over clasp in platinum

Annex 1
Split-seconds hand engaged
K

I

L

J
E
D

A
C

G

B

F
H

Split-seconds hand stopped

I

D

L

J
E
K

A
C

G

B

F
H

A
B
C
D
E
F

Isolator
Split-seconds column wheel
Split-seconds clamp
Isolator wheel
Split-seconds lever
Isolator spring and cap of split-seconds
column-wheel (swan’s neck)

G
H
I
J
K
L

Split-seconds control lever
Split-seconds control hook
Split-seconds wheel
Isolator pin
Split-seconds heart
Split-seconds clamp springs

Annex 2
Patek Philippe chronograph caliber CH 29-535 PS
Classic design with 6 patented innovations
The six patented innovations for Patek Philippe's proprietary CH 29-535 PS chronograph caliber launchedin 2009 are also incorporated in the new CHR 29-535 PS Q caliber of the split-seconds chronographmovement with perpetual calendar. They contribute to long-term reliability; the simpler and more precise
adjustability of specific functions; more convenient servicing; greater energy efficiency, and reduced wear.
These advantages safeguard the value and longevity of Patek Philippe timepieces, assuring that they will
delight future generations to which they are handed down.
1. Optimized toothing profile
Suppression of hand quiver or rebound at start. Vibration-free chronograph hand movement.
Increased efficiency. Reduced mechanical wear.
2. Precision adjustment of engagement depth at the column wheel
The large eccentric cap on the column wheel allows the very precise mesh depth adjustment of thechronograph wheels at the outermost end of the clutch lever.
3. Optimized synchronization of the clutch lever and brake lever
The clutch lever and brake lever are synchronized directly with a finger at the clutch lever.
This eliminates the complicated intermediate step via the column wheel.
4. Slotted minute-counter cam
Thanks to the slotted minute-counter cam, the chronograph hand can gently coast to a stop when reset.
5. Self-setting hammers
Self-setting hammers improve functional integrity and dependability.
6. Hammers pivoted between jewel bearings
The two hammers that reset the chronograph hand and the minute counter are independently
pivoted between jewel bearings on the same axis; each hammer is pressed against the respective
return-to-zero heart cam with its separate spring. This system optimizes the precise alignment of thehammers and improves their stability.
Further ingenious features
The caliber CH 29-535 PS movement has even more reliability and performance enhancing features.
In particular: the instantaneous 30-minute counter is much more complicated than a semiinstantaneous or a continuous counter. Thanks to its intricate construction, the small hand jumps
within fractions of a second to produce accurate, doubt-free readings. Another example relates tothe chronograph's driving wheel that is integrated directly into the going train and does not need
to be retrofitted by the watchmaker.