Draw
The reliability of the modern lever escapement depends upon draw; the pallets are angled so that the escape wheel must recoil a small amount during the unlocking. The draw holds the lever against the banking during the detached portion of the operating cycle. Draw angle is typically about 15 degrees to the radial.
Early lever escapements lacked draw (indeed some makers considered it injurious as a cause of extra friction in unlocking); as a result a jolt could result in the escapement unlocking.
Read more about this topic: Lever Escapement
Famous quotes containing the word draw:
“And the shuttle never falters, but to draw an encouraging conclusion
From this would be considerable, too odd. Why not just
Breathe in with the courage of each day, recognizing yourself as one
Who must with difficulty get down from high places?”
—John Ashbery (b. 1927)
“One may draw a dragon or a tiger, but it is hard to draw their skeletons; one may know a person’s face but it is hard to know his heart.”
—Chinese proverb.
“Human beings ought not to draw in their antennae at every ungentle touch, like supersensitive insects.”
—E.T.A.W. (Ernst Theodor Amadeus Wilhelm)