[ToC]

 

Rex Miller and Ellsworth M. Russel, Machinists Library, Theodore Audel & Co., 1980

DIAGRAM OF A THEORETICAL GEAR TOOTH

Of course, if the cylinders were gear blanks on which gear teeth were to be cut, the teeth could not project above the cylindrival

As aforementioned, the original surfaces of the cylinders remain on the contact line, and the diameters of these cylinders, or circules, provide the basis for the various gear tooth computations. The pitch circle is the line of contact of the two cylinders. The pitch circle is the reference circle of measurement, and is located one-half the distance between the top and bottom of the theoretical tooth.