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A minute wheel whose pinion drives the hour wheel. During setting it is driven by the intermediate wheel in the keyless works and it turns both the cannon pinion and the hour wheel, moving the hands. An hour wheel which fits over the shaft of the cannon pinion and whose shaft holds the hour hand. The hour wheel rotates once for every 12 ...
2. The gear trains used in clocks and watches have multiple stages of wheels and pinions in which the pinions have few leaves. Involute designs for these leaves would be undercut, making them too fragile and difficult to manufacture. 3. A large aspect of the design of watch and clock movements is the minimisation of friction.
The escapement is a mechanism in a mechanical clock that maintains the swing of the pendulum by giving it a small push each swing, and allows the clock's wheels to advance a fixed amount with each swing, moving the clock's hands forward. The anchor escapement was so named because one of its principal parts is shaped vaguely like a ship's anchor.
The foliot was a horizontal bar with weights near its ends affixed to a vertical bar called the verge which was suspended free to rotate. The verge escapement caused the foliot to oscillate back and forth about its vertical axis. [12] The rate of the clock could be adjusted by moving the weights in or out on the foliot.
Torque can be converted to linear force by meshing a rack with a round gear called a pinion: the pinion turns, while the rack moves in a straight line. Such a mechanism is used in the steering of automobiles to convert the rotation of the steering wheel into the left-to-right motion of the tie rod(s) that are attached to the front wheels.
In many cases, such as remote controlled toys, the pinion is also the drive gear for a reduction in speed, since electric motors operate at higher speed and lower torque than desirable at the wheels. However the reverse is true in watches, where gear trains commence with a high-torque, low-speed spring and terminate in the fast-and-weak escapement.
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small 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 torsion spring, known as the balance spring or hairspring.
Riefler clock, NIST museum, Gaithersburg, Maryland, USA. 54 inches (134 cm) tall. This clock served as the first US time standard, from 1904 to 1929. Clemens Riefler precision regulator clocks achieved accuracies of 10 milliseconds per day, [5] [6] and were guaranteed to be within 30 milliseconds. [7]