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:
“The press, the machine, the railroad, the telegraph are premises whose conclusion once a thousand years have passed no one has dared to draw as yet.”
—Friedrich Nietzsche (1844–1900)
“The logical English train a scholar as they train an engineer. Oxford is Greek factory, as Wilton mills weave carpet, and Sheffield grinds steel. They know the use of a tutor, as they know the use of a horse; and they draw the greatest amount of benefit from both. The reading men are kept by hard walking, hard riding, and measured eating and drinking, at the top of their condition, and two days before the examination, do not work but lounge, ride, or run, to be fresh on the college doomsday.”
—Ralph Waldo Emerson (1803–1882)
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—Elizabeth Cady Stanton (1815–1902)