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Elevators
An elevator (American English) or lift (English in the Commonwealth of Nations, Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems such as a Hoist (device), hoist, although some pump hydraulic fluid to raise a cylindrical piston like a Hydraulic jack, jack. Elevators are used in agriculture and manufacturing to lift materials. There are various types, like chain and bucket elevators, grain augers, and hay elevators. Modern buildings often have elevators to ensure accessibility, especially where Inclined plane, ramps aren't feasible. High-speed elevators are common in skyscrapers. Some elevators can even move horizontally. History Pre-industrial era The earliest known reference to an elevator is in the works of the Roman architect Vitruvius, who reported that Archimedes ( – ) built his first elevator probably in 236 BC. Sources ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counterweight
A counterweight is a weight (object), weight that, by applying an opposite force, provides balance and stability of a machine, mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves energy and causes less wear and tear on the lifting machine. Counterweights are often used in traction force, traction elevator, lifts (elevators), Crane (machine), cranes and fair, funfair rides. In these applications, the expected load multiplied by the distance that load will be spaced from the central support (called the "tipping point") must be equal to the counterweight's mass times its distance from the tipping point in order to prevent over-balancing either side. This distance times mass is called the Moment (physics), load moment. By extension, a counterbalance force balances or offsets another force, as when two objects of equal weight, power, or influence are acting in opposition to each other. Examples ;Trebuchet: There are fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
