Zenith "Chronometre", Movement No. 5362772, Cal. 135, 35 mm, circa 1950
A gentleman's timelessly elegant wristwatch - CHRONOMETER - with the legendary Zenith Cal. 135
Case: steel, push back, later added glazed push back. Dial: silvered. Movm.: 1/2 plate movement, Glucydur screw balance.
Zenith calibre 135
Ephrem Jobin introduced the legendary Zenith calibre in 1948; this was a time when many watch manufacturers competed for the highest scores in precision during observatory testing. Calibre 135 featured several technical innovations that enabled it to win a number of awards and prices in the tests; amongst those was a series of five consecutive prizes at the tests in Neuchâtel from 1950 to 1954. The movement type won a total of 200 awards, of which two thirds were first prizes.
Ephrem Jobin developed a larger barrel for the new calibre 135 to improve the isochronism and the power reserve; he also used an extra large balance to achieve higher precision during regulation (higher rotational inertia gives a more consistent performance without increasing the weight or the number of beats). This approach initiated a complete rethink of movement design: amongst other things the minute wheel was removed from the centre of the movement to create additional space for a larger balance. The model entered for observatory testing was fitted with a Breguet overcoil and an eccentric fine adjustment mechanism intended to guarantee a well-balanced friction and a perfect fine adjustment.
机蕊 非常好, 走動正常
机蕊 非常好, 走動正常