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Has Rolex auto mvmts always used mainspring clutch to prevent overwinding? Whilst it is true that the modern perpetual (automatic) movement has a slipping attachment on the end of the mainspring within the barrel, wrist watches have not always had such an attachment. I am at the moment restoring an early 8 3/4"' Rolex perpetual with a 'non automatic' mainspring fitted. The wearer can indeed wind the spring to the top and not wind further, however, the automatic work has a slipping clutch over the ratchet wheel that should start slipping when the barrel arbor has turned 5 complete turns. The period of slip is controlled by the grade of lubricant used. I'm not alone in being grateful that the design was not used more widely. The base movement measures 8 3/4"' but is stamped '9 3/4"' Hunter' and the O/D of the automatic-work measures 10 1/2"'. The movement is in a steel Oyster case with 5 fig. serial number 52*** Probably Model 1858. Tylden.
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