Help identifying pocket watch chronograph

[Skutt50]

I have this movement on my desc. It is mssing stem, crown and some springs which I can fix. The worst part is the broken pallet fork. (I don't understand how this happens but it is not the first movement I have seen with a broken pallet fork,)

Anyway I would like the movement identifird hoping to find a replacement pallet fork. My hope is to find a pallet fork from a similar movement (even one without the chronograph function)......

Any suggestions?

 

[Nickelsilver]

It's Valjoux, but can't find a visual match in my books. What's the diameter? Do you know what the extra wheel under the chronograph runner does? Looks like it interacts with the intermediate minute counter wheel, but that doesn't make sense... and the minute counter wheel has quite odd teeth, like on some instantaneous minute counters. Would be curious to see more detail in that area.

Once you measure it, the basic gear train and escapement will 99.9% interchange with other models of the same diameter.

 

[Skutt50]

Thanks Nickelsilver. Just what I was hoping to hear.

It is 19 linges or 43 mm across the main plate (Dial side).

I have not examined the chronograph mechanism yet. My first concern is to get it running and to identify what pats I need.

Here is a close up of the back side.


If you open the picture is a new window you should be able to enlarge it enough to see even the smallest pieces of dirt.

 

[Skutt50]

I did some checking of the mechanism. The wheel you asked about is indeed interacting with the intermediate minute counter wheel. That wheel in turn should interact with the minute counter wheel but the small pin is not reaching the minute counter wheel teeth. The pin is even bent slightly but no interaction. Should there possibly bee something attached to the pin like some small roller of similar?

 

[gmorse]

Hi Skutt,

Have you taken the return to zero hammer piece off? It should just lift off once its spring is disengaged, then we can see more clearly what the minute register indexing is doing, and whether it's an instantaneous mechanism of some sort, as the tooth form suggests.

Regards,

Graham

 

[Nickelsilver]

Yes if you get the hammer off it will make things more visible. I sent the last pic to a friend who's really tuned into rare Valjoux movements, maybe he'll come back with something.

 

[Skutt50]

Great info guys. Thank you very much.

Here is a picture withot the zero hammer.





Note that there is a broken spring that will keep the minute counter wheel in its distinct one minute intervall positions.

 

[gmorse]

Hi Skutt,



The red pin can't index the minute register in that position, but what's the purpose of that green circular piece? It's apparently able to rotate anti-clockwise driven by its spring, when the castle wheel allows it to. Is it moving the intermediate wheel closer to the register wheel so that the pin does engage? There must be some mechanism to disengage the minute register during flyback.

Regards,

Graham

 

[Skutt50]

Thanks Graham. You are soo right.

After some fiddling with the plate it came loose and as you suggested it moves the intermediate wheel so it engages and disengages, Now it turns the minute counter. The movement is full of dirt and sand? so things don't move easily.

If I find a new pallet fork I will take the entire movement apart and fully look into the mechanism.....