SERVICE, RESTORATION AND REPAIR SERVICES
OF
MARINE CHRONOMETERS
MAKING JEWELS FROM SAFFIRE ROD
MAKING A SPRING DETENT
REPLACEMENT OF A LOCKING STONE
THE TYPSY KEY
Every chronometer should have a tipsy key. These keys work by an internal ratchet which allows the instrument to be wound only in the correct direction which in most cases is anti-clockwise.
The importance of this cannot be stressed enough as to apply force to the fusee in the wrong direction can result in broken teeth on the maintaining ratchet, damaged fusee clicks and ratchet teeth and worst of all damage to the detent and escapement. The fusee key is designed to ratchet or slip if pressure is applied in the wrong direction thus protecting the instrument.
I often see the results of using the 'wrong' key. I can make tipsy keys of period/maker design to fit the chronometer and box.