Clockmaker's rounding-up tool

Clockmaker's rounding-up tool

This machine is used for correcting the tooth form of watch wheels.

The wheel is mounted between vertical centres so as to be free to rotate. The cutter is mounted horizontally and the pulley on the arbor is driven at a fair speed by a band which passes over a hand wheel.

In place of the usual milling cutter there is one with many cutting points which however extend only two thirds round the circumference, the gap being occupied by a guide which is offset at one end by the pitch of the wheel. The latter is thus rotated after each cut enough for the cutter to enter the next space.