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:
“Finding the perfect balance is getting harder and harder. We need to teach our children to be cautious without imparting fear, to learn right from wrong without being judgmental, to be assertive but not pushy, to stick to routines without sacrificing spontaneity, and to be determined but not stubborn.”
—Fred G. Gosman (20th century)
“Helpless, unknown, and unremembered, most human beings, however sensitive, idealistic, intelligent, go through life as passengers rather than chauffeurs. Although we may pretend that it is the chauffeur who is the social inferior ... most of us, like Toad of Toad Hall, would not mind a turn at the wheel ourselves.”
—Ralph Harper (b. 1915)