Maintain power while winding (clock related)

[LittleWatchShop]

I was watching a video about John Harrison and the longitude problem and was intrigued by the idea of maintaining power on the train wheels while winding.  With some google searching, I see how this is easy to do with weight-driven clocks.  I understand that there is a way to do this with spring-driven clocks but I have not found any good diagrams or videos.

So I appeal to my WRT friends on this matter.  Any good descriptions/diagrams out there in the interweb?  I will keep looking.

[nickelsilver]

See if you can find some disassembly photos of a marine chronometer. Maintaining power is only needed on movements with barrel and fusee (or weights); when you wind (the fusee) the moment that you are winding you are effectively cutting power to the train. On a normal watch or clock with going barrel, when winding you are actually increasing the power (a bit) to the train. On a precision clock that power cut could affect the timing, and something like a marine chronometer it could spell total disaster if suddenly the escape wheel was free-floating and the balance swinging at full amplitude.

 

But the actual function is just about identical between a weight driven clock and spring driven piece with fusee. The maintaining power is in the fusee. Also- back to marine chronometers- forgetting to let down the maintaining power (if possible) or blocking the train (if not) before removing the balance is an easy way to learn how to make spring detents, escape wheels, and locking stones .

[LittleWatchShop]

The "Fusee" was the key term to finding good material like here!!!

[JohnR725]

1 hour ago, nickelsilver said:

something like a marine chronometer it could spell total disaster if suddenly the escape wheel was free-floating and the balance swinging at full amplitude.

One of my friends used to service Marine clocks including a lot of chronometers including Hamilton. If you listen to him basically a chronometers an accident waiting to happen. He once gave a lecture at a nawcc regional meeting on chronometers but went off into the horrors of what happens if. I was waiting to see if all the people trying to sell their chronometers started looking for rope to hang him because it sounds like the best thing to do with their chronometers lock the balance wheel and put away safe and never touch it ever again.

Then one of the chronometers I acquired was one that had a total disaster. Escape wheel and balance staff pivots gone. I think just about all the tools associated with the escapement of course gone. Plus of course the escape wheel teeth were all bent over. A very interesting design of the escapement where works nice when it's working but if there's an issue it would be very bad.

[oldhippy]

Longcase regulator clocks. High quality clocks with a fusee normally what are called bracket clocks Vienna regulator clocks. Some good quality fusee pocket watches to name a few.

I have in the past restored a James McCabe English carriage clock which had maintaining power as you can guess it also was a fusee movement worth back in the 70's then around £10 thousand, to day about £80 thousand.