pitch circle

noun

, Machinery.

1. an imaginary circle within the profiles of the teeth of a gear, such that it rotates against a similar circle rotating at the same rate on a meshing gear.

pitch circle

noun

1. an imaginary circle passing through the teeth of a gearwheel, concentric with the gearwheel, and having a radius that would enable it to be in contact with a similar circle around a mating gearwheel

Word History and Origins

Origin of pitch circle¹

First recorded in 1810–20

Example Sentences

And to pencil in the teeth these circles must be fully drawn, as in Figure 234, in which P P is the pitch circle.

From Project Gutenberg

Where these divisions intersect the pitch circle are the centres from which all the teeth curves may be drawn.

From Project Gutenberg

When two gears of equal size mesh together, the pitch line, or the pitch circle, as it isp.

From Project Gutenberg

In fact, if a jewel pin was set to engage the fork on the pitch circle b a, the escapement would lock.

From Project Gutenberg

The circle b b represents the pitch circle of the jewel pin, and the circle at c c the periphery of the guard or safety roller.

From Project Gutenberg