Clockwork
In mechanical engineering, a clockwork is either a lightweight mechanical linkage, especially one involving multiple axles, or a complete mechanical device whose functioning relies on internal clockwork (in the preceding sense), especially where muscular effort is the sole source of operating power.
Overview
Often power for the device is stored within it via a winding device that applies mechanical stress to an energy-storage mechanism such as a spring, thus involving some form of escapement; in other cases, hand power may be utilized. The use of wheels, whether linked by friction or gear teeth, to redirect motion or gain speed or torque, is typical; many clockworks have been constructed primarily to serve as visible or implicit tours de force of mechanical ingenuity in this area. Sometimes clocks and timing mechanisms are used to set off explosives, timers, alarms and many other devices.
Phrases
Clockwork can also describe an action that is repeated in uniform order over and over, for example 'The postman does his rounds like clockwork every day.'
Examples
The most common examples are mechanical clocks - hence the name. Others include:
- Toys - often as a simple mechanical motor, or to create automata.
- Mechanisms to turn the lens of lighthouses before electric motors.
- Babbage's difference and analytical engines, and simpler mechanical calculators.
- Astronomical models, such as orreries whose history spans hundreds of years.
- Music boxes, which were very popular during the 19th century and at the beginning of the 20th.
- Almost all phonographs built before the 1930s.
- Low-powered electrical equipment, such as a clockwork radio, where an energy-storing spring accounting for much of the size and weight of the device spins a much smaller electric generator; such equipment is very popular in certain Third World situations where batteries and mains power (house current) may be scarce.
- A clockwork computer was described on BBC World on 30 September, 2005.