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 wheel, balance and/or wheel:
“Partisanship should be kept out of the pulpit.... The blindest of partisans are preachers. All politicians expect and find more candor, fairness, and truth in politicians than in partisan preachers. They are not replied to—no chance to reply to them.... The balance wheel of free institutions is free discussion. The pulpit allows no free discussion.”
—Rutherford Birchard Hayes (1822–1893)
“As deaths have accumulated I have begun to think of life and death as a set of balance scales. When one is young, the scale is heavily tipped toward the living. With the first death, the first consciousness of death, the counter scale begins to fall. Death by death, the scales shift weight until what was unthinkable becomes merely a matter of gravity and the fall into death becomes an easy step.”
—Alison Hawthorne Deming (b. 1946)
“Men seem more bound to the wheel of success than women do. That women are trained to get satisfaction from affiliation rather than achievement has tended to keep them from great achievement. But it has also freed them from unreasonable expectations about the satisfactions that professional achievement brings.”
—Phyllis Rose (b. 1942)