worm wheel

The frame e carries the worm-wheel a and the worm-gear b, which is operated by the crank f.

At the end of d′′ is fixed, in the usual manner, the worm-wheel for the dividing mechanism.

At each end of this screw it gears into a worm-wheel having journal bearing on the end of the slide rest feed screw as shown.

The cam c to be cut is bolted on to the face of the worm-wheel, which faces the headstock of the lathe.