Patek Philippe GENEVE CALIBER CH 28-520 HU Manuel D'instructions page 11

11
The World Time Chronograph
is the first watch
in Patek Philippe's regular collection to unite two
complications that rank among the manufacture's
most emblematic achievements. It perpetuates a
tradition that so far was expressed only in unique
pieces, such as wristwatch No. 862,442 dated 1940,
and updates this legacy to the state of the 21st cen-
tury. In the development of the new mechanical
caliber CH 28-520 HU, the watchmakers took inspi-
ration from the self-winding CH 28-520 column-
wheel chronograph movement with a vertical
clutch and from Patek Philippe's famous World
Time mechanism, a proprietary design with only
one time-zone selector which makes it extremely
easy to use. Thanks to the minimal-friction vertical
clutch, the chronograph hand (also referred to as
the trotteuse) can double as a permanently running
seconds hand.
This movement, finished in compliance with all
of the directives of the Patek Philippe Seal, is also
endowed with several trailblazing innovations,
among them the patented Spiromax balance
®
spring which improves isochronism.