Mainspring with separate braking spring?

[Simeon]

I have just bought a vintage Orfina 21 jewel on eBay (I haven't received it yet) and I am planning its future service.  It is an automatic fitted with an AS 1361 movement which I found a decent technical guide for.  The guide talks about the mainspring having a separate mainspring and 'braking spring' which is installed into the barrel before the mainspring.  I want to replace the mainspring as a matter of course (the technical guide provides the dimensions of the spring) - would it be OK to replace just the mainspring and reuse the braking spring or should I replace both?  What kind of end / termination would this spring have and how would it interact with the braking spring?  Does it just butt up against the end of the coiled up braking spring?  Obviously I am trying to answer these questions without having the watch to remove the spring and have a look.  Is this a typical form of mainspring?

Should I replace this two-spring arrangement with an equivalent size mainspring with bridle?

Here are some gratuitous photos, since every forum post needs photos

 

 

 

[RichardHarris123]

The bridal should be OK to reuse but I would buy an automatic spring with the bridal attached. 

[Neverenoughwatches]

28 minutes ago, Simeon said:

I have just bought a vintage Orfina 21 jewel on eBay (I haven't received it yet) and I am planning its future service.  It is an automatic fitted with an AS 1361 movement which I found a decent technical guide for.  The guide talks about the mainspring having a separate mainspring and 'braking spring' which is installed into the barrel before the mainspring.  I want to replace the mainspring as a matter of course (the technical guide provides the dimensions of the spring) - would it be OK to replace just the mainspring and reuse the braking spring or should I replace both?  What kind of end / termination would this spring have and how would it interact with the braking spring?  Does it just butt up against the end of the coiled up braking spring?  Obviously I am trying to answer these questions without having the watch to remove the spring and have a look.  Is this a typical form of mainspring?

Should I replace this two-spring arrangement with an equivalent size mainspring with bridle?

Here are some gratuitous photos, since every forum post needs photos

 

 

 

Tbh you might find something different inside, this watch looks to be a good 60 -70 years old. Hopefully its original but a repair guy might have altered it in some way, swapped to a one-piece spring or modded it in some way. The spring and its seperate bridle may well be ok to re-use, Its better to keep to the original set-up as mentioned earlier in another thread, manufacturers put a lot of time,effort and money into a watch's design .

Btw that a lovely looking watch face, i adore textured dials

Some re-luming to do as well, it'll keep you busy for a little while 

[Simeon]

1 hour ago, Neverenoughwatches said:

 

Some re-luming to do as well, it'll keep you busy for a little while 

Thank you for the reply. Yes, I guess someone else over its long history might have swapped the spring for something else. I guess I will need to wait until it's in my hands to find out. 

As for the lume. Yes, definitely going to relume. The hands obviously need doing. The dial seems to have dots on the indices and small triangles on the outside. Someone scared me that these might be radium. Not 100% sure of that but I will certainly take precautions not to breath any dust in when picking it out of the dial before adding lume. Looking for a lume powder that looks white / cream in the day and pale green when glowing. 

[Kalanag]

The original bridle (775) provides a hook accepting a standard spring for manual wound movements.

[JohnR725]

2 hours ago, Simeon said:

AS 1361 movement

the problem with technical literature he is it was printed at the time the watch was manufactured more or less. Then over time things have changed to like automatic mainspring is now come as one unit. So if you buy a mainspring for the watch is going to be one item it will no longer be a two-piece arrangement.

but it does look like a lot of watches used to say mainspring which is good.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=AS_1361

 

[Simeon]

33 minutes ago, Kalanag said:

The original bridle (775) provides a hook accepting a standard spring for manual wound movements.

Basically providing a lip for a normal mainspring to press against. Thank you. 

3 minutes ago, JohnR725 said:

the problem with technical literature he is it was printed at the time the watch was manufactured more or less. Then over time things have changed to like automatic mainspring is now come as one unit. So if you buy a mainspring for the watch is going to be one item it will no longer be a two-piece arrangement.

but it does look like a lot of watches used to say mainspring which is good.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=AS_1361

 

Thanks for chiming in John. Look at all of those available spare parts! It looks luxurious compared to the Soviet movements I am used to. 

I fully expect that when I pull the mainspring out it's already been replaced as a combination mainspring and bridle. What I will be careful about is checking, was this replacement right for the barrel / watch since I don't want to replicate someone else's mistake through buying the same mainspring which didn't actually fit in the first place. 

[Kalanag]

Here is a screenshot from a Youtube video which shows the self overlapping bridle (1) and how it is hooked to the mainspring (2)

Edited July 27, 2024 by Kalanag

[Simeon]

Looking through Cousins site, it appears that the replacement GR mainspring for this watch is described as 'automatic' so I expect a mainspring with a bridle. It also says that it has been discontinued. I think I can find the listed GR spring from other suppliers / eBay, who may have NOS (certainly they seemed to come in old school paper Nivaflex packets).