Odd mainspring outer hooking arrangement in a LeCoultre 481

[Stian]

Hello gurus, 

I'm working on an old LeCoultre watch with a 481 bumper movement. When taking the barrel apart, I found that the outer hooking does not stop against a notch in the barrel, rather there's a ring inside that barrel, see picture. 

Have you seen this arrangement before, and most importantly, can I use the mainspring winder to get the mainspring properly into the barrel again? 

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Thanks, 

Stian

[rogart63]

It's an automatic. If so it could be some kind of slipping thing. Or it can be broken? There shall not be a notch in the barrel as the movement is a bumber. I would get a new mainspring as it looks a little strange? 

Size for the mainspring is in the text. Somebody did shorten that mainspring so i guess the a easy to break? 

http://watchguy.co.uk/service-jaeger-lecoultre-automatic-calibre-481/

Edited June 25, 2017 by rogart63

[Stian]

Facepalm for the notch indeed

Thanks for your response! The spring is not broken, so this seems to be the friction slipping contraption probably way back then. I guess I can put this in first and then use the mainspring winder for the mainspring itself? If it goes wrong I can always order a new mainspring, I have the measurements.

Stian

[StuartBaker104]

Yes that is a separate clutch spring. As you say, if you can't reassemble it, you can buy a modern spring.

[vinn3]

that clutch spring is covered in de Carls watch repair book.  as I recall, it was patended by Movado,  it can be repaired.

[Stian]

Thanks a lot all, and de Carle is indeed a great source when working with these old beasts!

Stian