I recently acquired an original edition of Daniels' Watchmaking, and I'm reading it like a man obsessed. (By the way, why does the new revised edition by Daniels, that was due out late last year, keep getting pushed back for release in the US????)
I came across a rather unique tool called the Ingold Fraise, on page 133. After realizing what it can be used to achieve, namely, dressing wheels and pinions even further than a topping tool allows, I became extremely curious.
The tool itself is a bow operated "fraise", or specialized file, that files the teeth forms down to an even finer finish than a topping tool allows, and it does this with a cutter shaped like a gear, but with small ridges perpendicularly placed on the teeth. It's use thus files the gear teeth to a perfect epicycloid form with the correct fraise choice with an axial path-
i.e. it files the shape of the teeth away in the direction of the tooth engagement, from the bottom out to the tip radiating away from the center of the wheel, in a way no other tool can.
This leaves a very finely finished gear tooth profile that can dramatically improve precision in the watch.
I did a lot of research on the inventor, Pierre Frédéric Ingold, and found he worked with A.L. Breguet in his later years, and moved on to invent this amazing tool for patent on June 26 1856- an engineer named Le Blanc filed the patent for Ingold on his behalf, with the description of “machine suitable to retouch gear wheels, to form the epicycloid curve and to give them the required shape”. I found all of this info from 2 very good translated documents on the life of Ingold, done by the fantastic Richard Watkins.
As horological tools go, I realize that a near total lack of info on this tool, coupled with less than 3 pictures of it including Daniels' book, mean it must have been obscure indeed, used only by the most precise of watchmakers. But from the description of it, I would love to find the patent for it, or any detailed pictures or information on it. I belong to several good patent search sites, but nothing is showing up for this. From what I've found, the fraise gears themselves are very hard to find, and I was wondering if anyone still makes these things for watchmakers.
Finally, I was wondering if any of the more eminent among us have used or do use this tool, and could offer any insight on it.


