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The wheel and axle is a simple machine, consisting of a wheel attached to a smaller axle so that these two parts rotate together, in which a force is transferred from one to the other. The wheel and axle can be viewed as a version of the Lever , with a drive force applied tangentially to the perimeter of the wheel, and a load force applied to ...
A simple machine is a mechanical device that changes the direction or magnitude of a force. [1] In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. [2] Usually the term refers to the six classical simple machines that were defined by Renaissance scientists: [3] [4 ...
Human-powered transport is the transport of person(s) and/or goods using human muscle power.Unlike animal-powered transport, human-powered transport has existed since time immemorial in the form of walking, running and swimming, as well as small vehicles such as litters, rickshaws, wheelchairs and wheelbarrows.
Geared machines use worm gears to control mechanical movement of elevator cars by "rolling" steel hoist ropes over a drive sheave which is attached to a gearbox driven by a high-speed motor. These machines are generally the best option for basement or overhead traction use for speeds up to 3 m/s (500 ft/min). [51]
The Song Shi description of the gears in Yan Su's chariot, and the numbers of teeth on them, suggests that it worked this way, without a third road wheel. The gear ratios would have been correct if the pointing doll was attached directly to the large horizontal gear wheel, and the track-width of the chariot equalled the diameter of the road wheels.
The hand axe is the first example of a wedge, the oldest of the six classic simple machines, from which most machines are based. The second oldest simple machine was the inclined plane (ramp), [6] which has been used since prehistoric times to move heavy objects. [7] [8] The other four simple machines were invented in the ancient Near East. [9]
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Larger litters, for example those of the Chinese emperors, may resemble small rooms upon a platform borne upon the shoulders of a dozen or more people. To most efficiently carry a litter, porters either place the carrying poles directly upon their shoulders or use a yoke to transfer the load from the carrying poles to the shoulders.