pulley

pulleyless, adj.
/pool"ee/, n., pl. pulleys.
1. a wheel, with a grooved rim for carrying a line, that turns in a frame or block and serves to change the direction of or to transmit force, as when one end of the line is pulled to raise a weight at the other end: one of the simple machines.
2. a combination of such wheels in a block, or of such wheels or blocks in a tackle, to increase the force applied.
3. a wheel driven by or driving a belt or the like, used to deliver force to a machine, another belt, etc., at a certain speed and torque.
[1275-1325; ME poley, puly < MF polie MGk *polídion little pivot, equiv. to pól(os) POLE2 + -idion dim. suffix]

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In mechanics, a wheel that carries a flexible rope, cord, cable, chain, or belt on its rim.

Pulleys are used singly or in combination to transmit energy and motion. In belt drives, pulleys are attached to shafts at their axes, and power is transmitted between the shafts by means of endless belts running over the pulleys. One or more independently rotating pulleys can be used to gain mechanical advantage, especially for lifting weights. The shafts around which the pulleys turn may attach them to frames or blocks, and a combination of pulleys, blocks, and rope is called a block and tackle. The pulley is considered one of the five simple machines.

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      in mechanics, a wheel that carries a flexible rope, cord, cable, chain, or belt on its rim. Pulleys are used singly or in combination to transmit energy and motion. Pulleys with grooved rims are called sheaves. In belt drive, pulleys are affixed to shafts at their axes, and power is transmitted between the shafts by means of endless (ends joined together) belts running over the pulleys. One or more independently rotating pulleys can be used to gain mechanical advantage, especially for lifting weights. The shafts about which the pulleys turn may affix them to frames or blocks, and a combination of pulleys, blocks, and rope or other flexible material is referred to as a block and tackle. Archimedes (3rd century BC) is reported to have used compound pulleys to pull a ship onto dry land. Together with the lever, wedge, wheel and axle, and screw, the pulley is considered one of the five simple machines. See also belt drive; block and tackle.

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Universalium. 2010.

Look at other dictionaries:

  • Pulley — Pul ley, n.; pl. {Pulleys}. [F. poulie, perhaps of Teutonic origin (cf. {Poll}, v. t.); but cf. OE. poleine, polive, pulley, LL. polanus, and F. poulain, properly, a colt, fr. L. pullus young animal, foal (cf. {Pullet}, {Foal}). For the change of …   The Collaborative International Dictionary of English

  • Pulley — ist eine US amerikanische Melodic Hardcore Band aus Kalifornien. Sie sind seit der Gründung Anfang der 1990er Jahre bei dem Plattenlabel Epitaph Records unter Vertrag. Musikalisch bieten sie seit jeher Punkrock, wobei Pulleys Art von Punkrock… …   Deutsch Wikipedia

  • Pulley — est un groupe de punk rock américain fondé en 1996 en Californie par Scott Radinsky, ancien chanteur de Ten Foot Pole et star de baseball : il a joué onze ans en MLB avec les White Sox de Chicago, les Indians de Cleveland, les Dodgers de Los …   Wikipédia en Français

  • Pulley — Pul ley, v. t. To raise or lift by means of a pulley. [R.] Howell. [1913 Webster] …   The Collaborative International Dictionary of English

  • pulley — The noun has the plural form pulleys, and the verb (meaning ‘to work with a pulley’) has inflected forms pulleys, pulleyed, pulleying …   Modern English usage

  • pulley — early 14c., from O.Fr. polie (mid 12c.), from M.L. poliva, from Medieval Gk. *polidia, pl. of *polidion little pivot, dim. of Gk. polos pivot, axis (see POLE (Cf. pole) (2)) …   Etymology dictionary

  • pulley — ► NOUN (pl. pulleys) ▪ a wheel with a grooved rim around which a rope, chain, or belt passes, used to raise heavy weights. ORIGIN Old French polie, probably ultimately from Greek polos pivot, axis …   English terms dictionary

  • pulley — [pool′ē] n. pl. pulleys [ME poley < OFr polie < ML poleia < poledia < MGr * polidion, dim. of polos, pivot, windlass, axis: see WHEEL] 1. a small fixed wheel, sometimes turning in a block, with a grooved rim in which a rope or chain… …   English World dictionary

  • Pulley — For the band, see Pulley (band). For the village, see Pulley, Shropshire. For the American photographer, see Gerald P. Pulley. Pulley Pulleys on a ship. In this context, pulleys are usually known as blocks. Classification …   Wikipedia

  • pulley — [1] A grooved wheel carrying a string, rope, chain, or belt which turns the wheel. [2] Flat wheel with a V groove. When attached to a drive and drive members, the pulley provides a means for driving the compressor. See camshaft pulley crankshaft… …   Dictionary of automotive terms

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