Search results
Results from the WOW.Com Content Network
A grandfather clock (also a longcase clock, tall-case clock, grandfather's clock, hall clock or floor clock) is a tall, freestanding, weight-driven pendulum clock, with the pendulum held inside the tower or waist of the case. Clocks of this style are commonly 1.8–2.4 metres (6–8 feet) tall with an enclosed pendulum and weights, suspended by ...
A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is an approximate harmonic oscillator: It swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates.
The torsion pendulum was invented by Robert Leslie in 1793. [3] The torsion pendulum clock was first invented and patented by American Aaron Crane in 1841. [4] He made clocks that would run up to one year on a winding. He also made precision astronomical regulator clocks based on the torsion pendulum, but only four were sold.
The torsion pendulum has a period of precisely one minute; thirty seconds to rotate in one direction and thirty seconds to return to the starting position. This is thirty times slower than the 0.994 m (39.1 in) seconds pendulum typically found in a longcase clock, where each swing (or half-period) takes one second.
In later pendulum clocks the pendulum was suspended by a short straight spring of metal ribbon from the clock frame, and a vertical arm attached to the end of the verge rod ended in a fork which embraced the pendulum rod; this avoided the friction of suspending the pendulum directly from the pivoted verge rod.
It was used in the astronomical regulator clocks made by his German firm Clemens Riefler from 1890 to 1965, [3] which were perhaps the most accurate all-mechanical pendulum clocks made. An escapement is the mechanism in a mechanical clock that gives the pendulum precise impulses to keep it swinging, and allows the gear train to advance a set ...
Grasshopper escapement, 1820. The grasshopper escapement is a low-friction escapement for pendulum clocks invented by British clockmaker John Harrison around 1722. An escapement, part of every mechanical clock, is the mechanism that gives the clock's pendulum periodic pushes to keep it swinging, and each swing releases the clock's gears to move forward by a fixed amount, thus moving the hands ...
The earliest known example of a clockwork set-up is the Antikythera mechanism.This device functioned as a geared analogue computer after its creation during the first-century BCE timeframe, being somewhat astrolabe-like, and had been designed for calculating astronomical positions and particularly listing eclipses.