The balance wheel is the timekeeping device used in mechanical watches and some clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral spring, the balance spring or hairspring. It is driven by the escapement, which transforms the rotating motion of the watch gear train into impulses delivered to the balance wheel. Each swing of the wheel (called a 'tick' or 'beat') allows the gear train to advance a set amount, moving the hands forward. The combination of the mass of the balance wheel and the elasticity of the spring keep the time between each oscillation or ‘tick’ very constant, accounting for its near universal use as the timekeeper in mechanical watches to the present. From its invention in the 14th century until quartz movements became available in the 1970s, virtually every portable timekeeping device used some form of balance wheel.
Read more about Balance Wheel: Overview, Period of Oscillation, History
Famous quotes containing the words balance and/or wheel:
“As the House is designed to provide a reflection of the mood of the moment, the Senate is meant to reflect the continuity of the past—to preserve the delicate balance of justice between the majority’s whims and the minority’s rights.”
—Lyndon Baines Johnson (1908–1973)
“So I was glad of the fog’s
Taking me to you
Undetermined summer thing eaten
Of grief and passage where you stay.
The wheel is ready to turn again.”
—John Ashbery (b. 1927)