What do I have here?

skinnb1

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Oct 4, 2015
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I have been asked to see whether I can get a friend's clock working. It's a small desk clock with a digital dial. However it has a date of 1937 on the case and when I open it I find a pocket watch movement whilst the face claims an 8-day movement. I haven't found a maker's name yet but internet research suggests it may be a
Gédéon Thommen movement which seems to be sometimes described as a jumping hour movement. It indicates Swiss made on the face and on the movement.

I was told it had not worked in years although, for some reason, it started to tick as soon as I took it out of the case. It seems to have a conventional escapement. My research found late 19th century pocket watches with cylinder escapements. There are few jewels.

Can anyone tell me what I have here and whether my research seems reasonable. I have never seen anything like this and my internet research has revealed pocket watches but not clocks.

Thanks for any information you can provide.

Brian

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mosesgodfrey

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That’s a cool one! Love the digital readout!

8 day movements like this are a type of pocket watch movement, but it’s not uncommon to see them used in a desk clock.

When you say 1937 on the case, is that a presentation date/engraving? I’ve seen several digital designs from the late 1920s that are similar.

Often the case /inner cover will hold as much info about the “making” brand. Any marks/stamps seen would help, as might a view of the assembled item.

Otherwise, I’m hopeful others may know more about specific 8 day movement makers.
 
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skinnb1

NAWCC Member
Oct 4, 2015
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That’s a cool one! Love the digital readout!

8 day movements like this are a type of pocket watch movement, but it’s not uncommon to see them used in a desk clock.

When you say 1937 on the case, is that a presentation date/engraving? I’ve seen several digital designs from the late 1920s that are similar.

Often the case /inner cover will hold as much info about the “making” brand. Any marks/stamps seen would help, as might a view of the assembled item.

Otherwise, I’m hopeful others may know more about specific 8 day movement makers.
The 1937 date is an inscription so the clock could date from earlier. I will service the mechanism and see whether that reveals anything.
 

svenedin

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I can’t really see properly but it looks like a lever escapement to me and not a cylinder. If it really runs for 8 days it must have an enormous mainspring (for a pocket watch). The fact it runs when out of the case suggests that the time displaying mechanism is adding too much drag.
 
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skinnb1

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Oct 4, 2015
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I have now removed the balance and it is a lever escapement. Letting down the mainspring confirmed that the mainspring is much more powerful than usual. The bridge screws are very tight and there is some rust. I am moving cautiously as I don't want to shear any screws.

There are a couple of marks visible now that I have removed the balance cock but they are not very distinct and I can't describe them well. balance cock marks.jpg
 

skinnb1

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Oct 4, 2015
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Hi Brian,


These usually have an extra wheel in the train between the barrel and the centre wheel to provide the extended duration, which I think yours has.

Regards,

Graham
Thanks. I'm now struggling to remove the barrel bridge and close to giving up for fear of breaking something. There is a square post for hand setting which seems to sit above the bridge. The post is threaded to receive a screw which retains the hand setting control. As I try to lift the bridge the post lifts slightly and the digital minute dial also moves. I am not clear how this square post is attached and not clear what the dial side looks like. Is it safe to assume that the post is friction fitted to the pivot of the wheel below? I have tried moderate pressure but I am fairly confident that more pressure will break the pivot or something else. For the moment I will clean and lubricate what I can but any suggestions on how to proceed would be welcome.

post.jpg post2.jpg dialside.jpg
 

gmorse

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Hi Brian,

I expect it has a hollow centre arbor like most Swiss movements. The pin through the middle has to be driven out from the dial side.

Regards,

Graham
 

Bernhard J.

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Hi Graham,

I would rather opt for using a tool used for removing hands on the movement side (for this purpose I have this pair of Bergeon levers). Works well, even if the pin is rather stiff in the hollow arbour. Should work in this case also, if I take close look at the photos.

Cheers, Bernhard

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skinnb1

NAWCC Member
Oct 4, 2015
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Hi Graham,

I would rather opt for using a tool used for removing hands on the movement side (for this purpose I have this pair of Bergeon levers). Works well, even if the pin is rather stiff in the hollow arbour. Should work in this case also, if I take close look at the photos.

Cheers, Bernhard

View attachment 730129
Thank you both Graham and Bernhard. I plucked up courage to take the hand lever approach as I was uncertain what was beneath the dial and was afraid of damaging something there. Now I have it all apart I can see that one gear wheel has 2 pinions. I haven't seen that before, but I am a novice.

dialsidedone.jpg barrel.jpg
 
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gmorse

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Hi Brian,
Now I have it all apart I can see that one gear wheel has 2 pinions. I haven't seen that before,
That's the third wheel, but here it isn't driven from the centre wheel, (which is normally the second wheel), but from the 'extra' wheel. The second pinion on the third wheel drives the centre wheel, (which is normally driven by the great wheel on the barrel).

Regards,

Graham
 

skinnb1

NAWCC Member
Oct 4, 2015
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I have completed the servicing of this clock which now seems to be running well. The figures on the minutes dial could be brighter but I preferred not to interfere with them. The hour dial tends to interfere with the minutes dial and I have overcome that by failing to tighten the hour dial completely. I have also replaced the old and yellowing perpex or similar material which protected the dials.

completed.jpg
 

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