FIG. 8.—CROWN AND LANTERN GEAR
When a small gear engages a large one, the former is commonly known as a pinion.
FIG. 9.—SPUR AND PINION GEAR
FIG. 10.—BEVEL FRICTION GEARS
If two friction wheels are to turn at right angles one to the other, they must have conical bearing surfaces, as in Figure 10. The angle between the shafts of the two gears and the relative size of the gears may be changed as desired, provided each cone surface has its apex at the intersection of the two shafts or axes. It is easy to understand how such conical friction gears may be converted into toothed bevel gears (Figure 11), by forming teeth on the conical surfaces, and it will be evident that the teeth must taper toward the apex of the two cones. Two bevel gears of equal diameter, and with shafts set at right angles one to the other, are known as miter gears.
FIG. 11.—TOOTHED BEVEL GEARS