March 15, 2005, 11:58Frank J. Menez
Marsh Auto Hairspring Stud Pin Machine
* Hair spring stud pin is a tiny tapered pin used to secure the end of hairspring in hole thru stud.
When Charles W. Fogg, pantentee of the safety pinion was a young apprentice, hairspring stud pins were filed by hand from wire, held in a pin vise, twirled by thumb and finger. That was the old way. Later on a lathe and rotary file was employed, however the lathe had to be stopped, completed pin cut off, chuck loosened, wire advanced to correct distance for another pin. Wire only a few inches long could be used. This was a marked improvement but still very tedious. With Marshe's machine long lengths of wire were automatically fed thru the spindle, held in collet,rotated against a rotary file till completed, then sheared off at the correct length. These tiny tapered pins were produced at a rate of 20-35 per minuet according to the material used.