In like manner, if either the same or any other rolling curve be rolled the opposite way, on the outside of the pitch-circle BB, so that the tracing point T shall start from A, it will trace the face AT of a tooth suitable to work with a flank traced by rolling the same curve R with the same tracing-point T inside any other pitch-circle.
If the same rolling curve R, with the same tracing-point T, be rolled on the outside of any other pitch-circle, it will have the fare of a tooth suitable to work with the flank AT.
For a smaller pitch-circle the flanks would be convex and in- curved or under-cut, which would be inconvenient; therefore the C smallest wheel of a set should FIG.
The effective radius, or radius of the pitch-circle of a circular pulley or drum, is equal to the real radius added to half the thickness of the connector.
Let BB be part of the pitch-circle, and a the point where a tooth is to cross it.