What is this for?

[kdf]

I suppose it makes circle around the oil sink, but I'm not sure. Center has spring behind it... G.Boley, Germany, 35

 

[Dave Coatsworth]

It's a clock hole closing punch.

 

[Dr. Jon]

Just to add a bit. The spring loaded center goes onto the hole so make the deformed metal stay concentric with the existing hole.

 

[Betzel]

After seeing riveted "daisy tapping" of a circle of punch marks on clock plates, and similar marks on old pocket watches, these always seemed like something I should have on hand, but I'm beginning to have my doubts about using them at all these days. Many of the better "whacks" I've seen have been reasonably well done (maybe on iffy pivot fits where you might or might not), but it is permanent.

Many look very much like bushings until I take a closer look and see it is solid. I suppose in the day when people could not afford to pay a man to bush a clock (or lightly jeweled pocket watch) by hand, maybe on lower-end timekeepers with limited lifespans, punching may have made economic sense, but do any modern repairers "correctly" use these any more? When would yes be a good answer?

The oldest clock bushing "machines" I have seen seem to be from WWII or after, so perhaps they were all done by hand or punched before that? Use of these also means removal of more original plate when a bushing job has to be done by the next guy. Just thinking out loud...

 

[gmorse]

Hi Betzel,

When would yes be a good answer?

I can't think of any circumstances when it would be appropriate.

Regards,

Graham

 

[karlmansson]

I agree with Graham. Closing holes in plates is an imprecise and short term solution. The hole will never just be "enlarged" but always worn to one side and so be oval. Punchung an oval hole will either just provide a better fit in one direction or pinch the pivot. These punches will also only move material on one side of the plate, making the contact area smaller on the pivot. Uprightness of the corresponding wheels and arbors is not ensured. They will also not adress any embedded grit that may have caused the wear in the first place. Bushing will solve all of the above and restore the clock to original working condition.

 

[wefalck]

The 'common' German term for these punches are 'Pfuschpunzen', meaning botcher's punches ...