Leeds Pocket Watch Swiss Movement

[tmac1956]

All:

I’m starting the disassembly process of an old English pocket watch and I have a question. When I tried to remove the canon pinion it was really tight. Not having worked on one of these before, I didn’t want to break anything by putting too much pressure on it. So, I stopped and using an old oiler I put a few tiny drops of PB Blaster between the wheel pivot and the cannon pinion hole. I think it’s just really dirty and therefore stuck to the wheel pivot but I just wanted to ask if anyone has worked on this type of movement who might offer some input.

Here’s an image:

Thanks,
Tom

[Bob Tascione]

Hi Tom,
It’s difficult to tell from your pic angle what type of design you have. There’s the common cannon pinion setup that we see on most modern watches where the cannon pinion carries the minute hand and slips on the center wheel arbor post and then there are less common designs where the clutching action is provided by a means other than friction between the cannon pinion and the center wheel arbor post. In one case the minute hand fits onto the post which sticks up beyond the tip of the cannon pinion. This type of setup uses a hollow center wheel arbor through which a pin/post passes through from the other side of the movement and extends out beyond the end of the cannon pinion to allow for the minute hand. Its clutching tension is provided by the slight friction fit between the center wheel arbor wall and the pin that passes through it requiring a different but simple method of removal of the pinion. Edit: I should add that not all of these designs have the post extending up beyond the cannon pinion end. Some may have the minute hand still attaching to the cannon pinion pipe but the clutching action is usually (not always as there are also designs that use tension washers but that’s not the case here) still provided between center arbor hole wall and the post.
From the pic angle I’m not able to see whether the center pin extends beyond the pinion on the dial side or is flush with the cannon pinion pipe end.
Any chance you can put a pic up that shows a different angle?
Thanks,
Bob

[tmac1956]

Bob:

I’ll try to put a better picture up but the center pin does appear to extend beyond the pinion. Since I’ve never seen one like it, I figured that I needed more information. It’ll probably be tomorrow before I can get another picture posted.

Thanks!
Tom

[Bob Tascione]

Ok Tom, no need for a pic if you’re sure about it being higher than the pinion.
If the minute hand fastens onto this post then you can be certain its tension is derived from friction between the post and the center wheel arbor hole wall. In this case the extended post also facilitates easy removal of the post from the pinion by tapping it with a brass hammer or punch. It’s important to support the opposite end of the center arbor and pinion on a bench block or staking set with a hole just large enough for the stop flange of the post to pass through. The fit between the post and the cannon pinion should be fairly tight while the fit between the post and center arbor hole is a light press fit. Also it’s a good idea to check the end of the post where the hand fits and make sure no burr or mushrooming has occurred from someone in the past trying to knock the pin out with a steel punch while not providing a hole for the pin to pass out of the center arbor. If you see mushrooming just stone it back to the correct shape and then clean the abrasive off with Rodico before driving it through and out of the pinion and center wheel arbor.

Bob

[tmac1956]

Bob:

Great information! The staking set is what I’ll probably use. I think you just saved me from tearing this one up. Here are a few pics just to be safe.

Thanks!
Tom

[Bob Tascione]

Good to hear Tom,
Yes that should work for you as long as you’re sure that the post extending above the pinion tube isn’t part of the tube; ie not a turned shoulder but rather a pin passing through the tube that the pinion is pressed onto. From what I can see from the overhead shot it looks like two separate pieces.
Good luck and please let me know how it turns out.
Bob

[tmac1956]

Bob:

Here is a closer shot which seems to indicate a joint between the post and the pinion. What say you?

Thanks,
Tom

[Bob Tascione]

Looks good from here Tom.
I think I would support the other side of the center arbor and go for it. Shouldn’t have to tap too hard.
Good luck,
Bob

[tmac1956]

All:

For those who haven’t seen this type of 2nd wheel/arbor mechanism before, I thought I would post a few pics of it after removal. It is precisely as Bob described it. David Pierce happened to be visiting this weekend so he made sure that I didn’t beat the heck out of it while trying to remove it. A little PB Blaster didn’t hurt any either. Clearly, the movement has yet to be cleaned.

Just FYI…

Tom

[randy]

Thanks for sharing this Tom.
And to Bob for the great ( as always ) instructions ….
And to David for keeping you restrained !!

Best
Randy

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