WatchProSite|Market|Digest

Horological Meandering

Talking about big dates, what about this one?

 


Photos: Monochrome







There is some advanced engineering involved in this date complication to power instantaneous date-changing without affecting chronometric accuracy. As described in Monochrome:


"Suppose the power needed for the date change, was restrained from the main spring, through the gear train, all at once. That would cause a huge fluctuation of power in the gear train that also drives the escapement, and therefore influence the timekeeping performance negatively. The solution is to build up that power gradually, over the 24 hours of a day. The mechanism to build up that power, comprises a double cam system and a large lever. One of the cams accumulates energy during 24 hours. This arms the large lever continuously, releasing it every 24 hours onto a 31-tooth wheel. The second cam plays the crucial role of a brake, by controlling a spring-mounted lever. This device keeps the large date discs permanently immobile, releasing them for just a fraction of a second every 24 hours to allow the instantaneous jump. The result is the biggest instantaneous large date and it changes within 1/100th of a second."

Interesting thread Emmanuel. Thanks!


  login to reply