pitch surface

American  

noun

1. (in a gear or rack) an imaginary surface forming a plane pitch plane, a cylinder pitch cylinder, or a cone or frustrum pitch cone that moves tangentially to a similar surface in a meshing gear so that both surfaces travel at the same speed.

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Etymology

Origin of pitch surface

First recorded in 1885–90

Example Sentences

We may also say that the pitch circle is the edge of the pitch surface.

From An Introduction to Machine Drawing and Design by Low, David Allan

Pitch Circle.—A section of the pitch surface of a toothed wheel by a plane perpendicular to its axis is a circle, and is called a pitch circle.

From An Introduction to Machine Drawing and Design by Low, David Allan