Page:Practical Treatise on Milling and Milling Machines.djvu/172

Rh Cutting Teeth in Spiral Gear

The machine is shown, in the illustration above, set in position to cut a left-hand spiral gear of 45° angle.

The gear is mounted in the same manner as in several previous operations, but instead of remaining stationary as the table advances, it is rotated by means of the required change gears to give the correct lead to the teeth. The table is fed longitudinally from left to right.

A right-hand spiral gear of the same angle may be cut in the same manner by setting the table to 45° the other side of zero and leaving put the intermediate or reverse gear.