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For example, a bench vise consists of a lever (the vise's handle) in series with a screw, and a simple gear train consists of a number of gears (wheels and axles) connected in series. The mechanical advantage of a compound machine is the ratio of the output force exerted by the last machine in the series divided by the input force applied to ...
Examples of rope and pulley systems illustrating mechanical advantage. Consider lifting a weight with rope and pulleys. A rope looped through a pulley attached to a fixed spot, e.g. a barn roof rafter, and attached to the weight is called a single pulley. It has a mechanical advantage (MA) = 1 (assuming frictionless bearings in the pulley ...
The motion of the lever's end-point describes a fixed orbit, where mechanical energy can be exchanged. (see a hand-crank as an example.) In modern times, this kind of rotary leverage is widely used; see a (rotary) 2nd-class lever; see gears, pulleys or friction drive, used in a mechanical power transmission scheme.
The lever is operated by applying an input force F A at a point A located by the coordinate vector r A on the bar. The lever then exerts an output force F B at the point B located by r B. The rotation of the lever about the fulcrum P is defined by the rotation angle θ in radians. Archimedes lever, Engraving from Mechanics Magazine, published ...
A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain. The earliest evidence of pulleys dates back to Ancient Egypt in the Twelfth Dynasty (1991–1802 BC) [1] and Mesopotamia in the early 2nd millennium BC. [2]
Lever toys are mechanical toys that use the mechanical advantage of a lever to transmit and transform movement. Lever toys can use cranks and cams too. Pulley toys. Pulleys are very similar to gear wheels but two elements are connected by a metal chain or belt from elastic strong material (for example rubber.)
The Way Things Work is a 1988 nonfiction book by David Macaulay with technical text by Neil Ardley.It is a whimsical introduction to everyday machines and the scientific principles behind their operation, describing machines as simple as levers and gears and as complicated as radio telescopes and automatic transmissions.
Power flow through a machine provides a way to understand the performance of devices ranging from levers and gear trains to automobiles and robotic systems. The German mechanician Franz Reuleaux [ 45 ] wrote, "a machine is a combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to do ...