Pellaton winding system

Hello. I have a couple questions I hope won't be too difficult to answer.

1) When was the Pellaton winding system actually patented? I've seen plenty of articles talking about it from 1946 and some improvements made in 1950, but I can't seem to find the date of the patent.

2) What are some of the calibers that used this system from the 50's and 60's?

Thanks!

Pellaton - still being used today in IWC Cal..

but probably the IWC Calibre with the most volume produced by IWC which contained this mechanism, was the Cal 85 series, like 853, 8541b etc. etc.

Read all about it in this fine article written by our Forum Moderator at
www.iwcforum.com/Articles/Calibre85Family/Text.html

IWC's Calibre 85 Family

Pellaton winding system patents

The first patent was dated 14 June 1946 and was numbered CH254578 and was followed by some changes with patents CH284841 and CH297477.

These can be found on the European Patent Office on the link below, Do a patent number search and enter the patent number, ie CH254578

Cheers from the cellat

European Patent Office

for the vintage calibres using the system...

Thank you gentlemen!

Any luck on a reliable list for dating a watch by the serial numbers?

shakes head in amazement

the wondrous dedication and enthusiasm of IWC collectors - inspiring !