pitch line

noun

, Machinery.

1. pitch circle.
2. an imaginary line within the profiles of the teeth of a rack, such that it moves against, and at the same rate as, the pitch circle of an engaging pinion.

Word History and Origins

Origin of pitch line¹

First recorded in 1790–1800

Example Sentences

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

From Project Gutenberg

You will note, from the above illustration, that the actual pitch line should meet the junction of the chord line and top line.

From Project Gutenberg

The pitch line is then drawn at a radius of 1.606 of the pitch from the worm axis.

From Project Gutenberg

The mortise spur-wheels have a diameter of 22 feet at the pitch line, with two rows of teeth, each 15 inches face.

From Project Gutenberg

The teeth are designated for measurement by the pitch; the height or depth above and below pitch line; and the thickness.

From Project Gutenberg