hi dose anyone know were i may find a mainspring for a early 1900s patek philippe pocket watch? thanks james

James, I can't make any promises I'll have one, and it may take a little while for me to search and get back to you, but if you can let me have the following info I'll take a look in my stash.

I need the height, thickness and length of the spring, plus internal diameter of the barrel, and a photo of the hook at the barrel end.

Also let me know if it's a blued steel type spring or a later 'unbreakable' white alloy type -I'll need the dimensions in mm to 2x decimal places BTW.

All my springs come in every Swiss flavour imaginable in terms of sizing, hence the need for measurements.

If you can also measure the smaller diameter on the dial plate just under the top ridge (which sits on the case) and in mm again, plus any other details you can give me on the movement, I may be able to find it in my parts books.
The diameter will help me find the 'ligne' size of the movement.

Best regards

John

hi thank you john i will get all that info to you tomorrow.i will need to take it apart to get all that.thanks james

hi john i have that info the main spring is blue steel and its 1.79 x .15 x 52 long, the spring is hole end,the barrel i.d. is 16.20,the movement under the dial is 38.21 and the info on the movement says s.n.147924 and it says pat.jan.13 1891 and also it says eight adjustments and 20 jewels.i also could use a new barrel as the nub dosnt catch the spring to well ill bet you dont have one of them so ill have to find a way to fix it.well good luck and thanks james

Thanks James,

I'll make a start having a root through all my stuff.

I don't think I have any 'hole end' springs, they're more likely to have a hook rivetted or spot welded on the end. It's just a slip of spring but it latches into the hook inside the barrel - you may get away with it, or perhaps form a hole yourself by punching the spring.

Must confess I've never seen a hole end spring at the barrel end in a Swiss watch before, except for the barrel arbour.

Definitely won't have a barrel, but if you can post a photo of the hook area it'll give me a better idea what the attachment is like.

Best regards

John

hi i still have not figured out how to post photos on this website but i can tell you all thats inside the barrel is a little nub that the hole catches on.i know what you mean about the end as i have many swiss springs my self and none of them are hole end.as far as putting a hole in one i have not yet figured how to do that.thanks james

Leon Harris was kind enough to use his magic laser to put the requisite hole in an extremely thin mainspring I needed to power the minute repeater function of an Ed. Koehn watch. The spring was no wider than a needle. It was so hard finding a spring of the proper size that my two regular watchmakers were afraid to try drilling a hole in the spring for fear that they would ruin it. Leon's e-mail address is harrislj@msn.com.

hi thanks for the info i have heard a lot about his magic.i will have to wait to see what i can get for a spring. james

James, just a short note letting you know I've not forgotten you, and still searching!

Most of my springs came from a friend who quit repairing, but he needed the container they were in so just tipped the lot into a cardboard box!
There's maybe a thousand+ to sift through, pocket and wrist sizes, and all mixed up! ............. so I'm using the search to categorise them, otherwise it'll never get done.

I'm a bit baffled by the hole end on the spring, does your spring have another loose piece like a dart - the flat end hooking into the barrel wall and the other end, the dart which fits the hole in the spring?
I've remembered I came across this arrangement once in a Hebdomas 8 Day pocket watch.

The end of the spring should hinge on this 'dart' as the spring is wound and moves away from the barrel wall, otherwise it will probably slip off the hook.

One other thing to check too, and Ethan's comments brought it to mind; is your spring parallel all the way along, or does it taper?
Some of these high end watchmakers used fancy spring profiles to maintain consistency of power as they unwound!

John

hi john there is nothing inside the barrel except a small nub the hole catches on.i know what you are talking about what is happening when i wind it is just as you say i wound it once with the cap off the barrel when you get it half wound it moves away from the barrel and slips.aside from this problem this is a very nice old watch.would it be real wrong to drill a hole in the cap and barrel to fit a t-end spring?i would hate to do that however if i have no choice i my. thanks again james

<<<would it be real wrong to drill a hole in the cap and barrel to fit a t-end spring>>>

Aaarrgghhhh Jaaaaaames, Toooooo right it would! Don't Do it!

If it was one of those scabby old Railroad watches it wouldn't fuss me at all, but this is a Patek!

From what you describe, I think there's a small slip of spring gone AWOL at some point, either that or it's had the wrong type spring fitted as a replacement.

If you have an old mainspring anywhere of a similar depth and height to that fitted, cut a piece about 20% the circumference of the barrel and trim one end to a shallow taper - like a pencil point but rounded off at the end, then stone all edges smooth.

What you're looking for is a neat fit in the hole end of the spring, and a clean latch into the barrel hook.

You'll have to play around with the shape of the dart and the spring end so it sits neat with the spring unwound into the outer part of the barrel.
Try it out and see how it goes!

The alternative is a standard spring end which is the type I have here (when I eventually find the right size - close but no cigar yet!).

These have a small tab spot welded on the spring end, which sits slightly raised and back along the spring so it latches into the barrel hook as it's wound up.

Other methods used for spring ends, is to soften the end of the spring and fold it back, so making a hook, or, same again, but with a shorter flap, then also insert a separate slip of spring under the piece that's folded back so it traps it. This slip will then hook into the barrel wall and also hinge slightly.
This method creates a bit less stress on the spring end too when wound than a welded or folded spring end.

You may need to dress the barrel hook a touch too, as it's probably got rounded off a tad with the spring slipping off.
The hook will be either a steel insert (rivet) or simply the edge of the barrel wall punched from the outside, so raising a flap inside the barrel.

John

hi again dont worry its one thing to talk about drilling that barrel and cap and another for me to do it.i have been trying to fix this for a long time now the part that gets me is this ran when i took it apart i just wanted to service it.i have seen the springs it has a end that folds back.so let me see if i understand that part that part of the end that gos backwards catches that nub so when the spring starts to move away from the barrel it digs in?if that is the case then it dosn't even use a hole end spring and someone put that in there because they did not have the proper spring is this possible? thanks jamse

James, when you took the spring out, did it twang all over the place when it came out of the barrel?
(we've all had it happen, and those that say they haven't are telling porkies)

If so, it's possible that a small 'dart' got shot somewhere never to be found again - that dart, or slip of spring is likely to have been the piece the mainspring end hinged on ......... or has the mainspring slipped as long as you've owned the watch .......... if so it's either probably had the wrong type spring fitted or someone else lost the dart before you got the watch!

BTW, does your watch have Geneva stopwork fitted on the barrel?
It will look like a polished Maltese cross on the barrel arbour end, which meshes with a disc that has a 'pip' shaped into one edge, they'll be fitted on the barrel cap.

If all you can see is a sort of 'figure of 8' cut into the cap, it's probably been broken and chucked away.

John

hi john ill be sorry when this is over i look forward to talking to you each eve.when i remove a spring i cup my hand around it like a 5 legged spider so it comes out somewhat controlled its possible something could come out but not likely.on this spring the hole was at the very end so there could be nothing beyond it.the geneva stopwork is complete.so tell me hows the weather there?we have snow here in denver colorado U.S.A. sincerly james

As the saying goes James, 'It ain't over 'till the fat lady sings' ....... and I ain't fat, can't sing, and definitely Not a lady

Ok, the stopwork puts a different angle on it now, don't know why I never asked in the first place!

Questions!
What is the shape of the hole in the spring?
What is the shape of the barrel hook?
Does the barrel hook match the shape of the hole in the spring, or are they a mismatch?

Can you Please get a Digi-camera .........

If the hole and hook are a perfect match, the spring should work when using Geneva stops if set up properly!

Check the edge of the hole and the hook, they should be crisp and not rounded over - I recon they will both be rounded though if the spring's been slipping, and will need work.

My thoughts ..... if I'm on the right track!

Assuming the spring is correct for the barrel, then the unwound spring pack will sit far cleaner over this type hook arrangement than a spring with a rivet type flap, which tends to make the unwound coil pack sit a tad flatter in that area.
Very good for clean unwinding!

With Geneva work, the spring generally shouldn't get wound up far enough to have the outer spring coil leave the barrel wall.
In theory at least it shouldn't then come off the hook, because there will most likely be a coil sat over it, or enough around the barrel to keep the spring eye in tight contact with the hook.

I've never read anywhere a definitive procedure for setting Geneva stops, so I generally treat them in a similar way to setting a fusee barrel.

If the spring is pre-loaded by (say) 1/2 to 3/4 of a turn of the barrel arbour, it should be a reasonable starting point to set the stopwork.

As the stop then prevents the spring being wound to its fullest extent, and assuming the spring is the correct length (not too short), then there'll likely be a coil or so remaining at the outer edge of the barrel keeping the hole end against the barrel wall.

If there's been way too much pre load to start with when the stop work was set, it will mean more spring will be wound from the outer end exposing the hook as the spring slopes towards the centre of the barrel.
As the hook and hole are not in this case designed to pivot, the spring end will slip off.

Sometimes, an extra dollop of pre-load gets set to get around a weakened mainspring, and this could cause the slippage you're seeing.

All that happens by increasing preload, is you wind more spring from the inner end which gets taken from t'other, because the stopwork always turns the same fixed number of rotations before it locks.

Phew! Hope you followed all that gibberish, brevity never was a strong point of mine!

Aah the good ole British weather! Had snow and sub zero's a couple of days ago, and today 14 Deg and bright sun, all washed down with a howling gale and freezing wind chill straight off the sea!
Spring's well on it's way though!

John

hi john wow thats a lot to ponder i think part of my problem is that nub in the barrel is wore on the edge that catches the hole in the spring.however something else you said made me think i pre wound the spring a little before i before i put the stop together maybe i gave it a little to much.i was trying to get it to work in the middle of the spring for good time keeping through out but as i said i could see (with the cap off)the spring would move away from the barrel and then slip.maybe that spring is to stiff and maybe if i dont pre load it it will not slip i will try that tomorrow.i wish i had a file small enough to put a better edge on that nub.i have always wanted to go to england and eat fish and chips and have a pint however i am not a young man and will probability will never get to.god save the queen. sincerly james

James, just dropping by to let you know you're not forgotten.
I'm struggling to find a suitable mainspring for you (as well as going crosseyed sorting all this stuff)!
I've not thrown the towel in yet, but it's looking pretty unlikely I'll have something suitable now.

If your spring is hopping off the hook, you're most likely winding on too much pre-load or the spring's been shortened(unlikely really).
Try backing off the pre-load half a turn and try again.

You could try honing a sharp flat point on a sewing needle to use as a fine graver to sharpen the barrel hook, or, if the hook is punched through from the outside wall, mount the barrel on a rod with similar curvature and gently punch it a tad further in.

Best regards

John

hi john i've tried backing it off all the way and can wind it 3/4 of the way around the geneva stop before it slips. that sewing needle thing sounds worth trying.