Pulley block

Pulley block
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 sense, cf. F. poutre beam, originally, a filly, and E. easel.] (Mach.) A wheel with a broad rim, or grooved rim, for transmitting power from, or imparting power to, the different parts of machinery, or for changing the direction of motion, by means of a belt, cord, rope, or chain. [1913 Webster]

Note: The pulley, as one of the mechanical powers, consists, in its simplest form, of a grooved wheel, called a sheave, turning within a movable frame or block, by means of a cord or rope attached at one end to a fixed point. The force, acting on the free end of the rope, is thus doubled, but can move the load through only half the space traversed by itself. The rope may also pass over a sheave in another block that is fixed. The end of the rope may be fastened to the movable block, instead of a fixed point, with an additional gain of power, and using either one or two sheaves in the fixed block. Other sheaves may be added, and the power multiplied accordingly. Such an apparatus is called by workmen a {block and tackle}, or a {fall and tackle}. See {Block}. A single fixed pulley gives no increase of power, but serves simply for changing the direction of motion. [1913 Webster]

{Band pulley}, or {Belt pulley}, a pulley with a broad face for transmitting power between revolving shafts by means of a belt, or for guiding a belt.

{Cone pulley}. See {Cone pulley}.

{Conical pulley}, one of a pair of belt pulleys, each in the shape of a truncated cone, for varying velocities.

{Fast pulley}, a pulley firmly attached upon a shaft.

{Loose pulley}, a pulley loose on a shaft, to interrupt the transmission of motion in machinery. See {Fast and loose pulleys}, under {Fast}.

{Parting pulley}, a belt pulley made in semicircular halves, which can be bolted together, to facilitate application to, or removal from, a shaft.

{Pulley block}. Same as {Block}, n. 6.

{Pulley stile} (Arch.), the upright of the window frame into which a pulley is fixed and along which the sash slides.

{Split pulley}, a parting pulley. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

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Look at other dictionaries:

  • pulley block — noun a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope • Syn: ↑pulley, ↑pulley block, ↑block • Hypernyms: ↑machine, ↑simple machine •… …   Useful english dictionary

  • pulley-block — noun a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope • Syn: ↑pulley, ↑pulley block, ↑block • Hypernyms: ↑machine, ↑simple machine •… …   Useful english dictionary

  • block and tackle — 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… …   The Collaborative International Dictionary of English

  • 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 stile — 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… …   The Collaborative International Dictionary of English

  • block and tackle — ► NOUN ▪ a lifting mechanism consisting of ropes, a pulley block, and a hook …   English terms dictionary

  • block and tackle — noun pulley blocks with associated rope or cable • Hypernyms: ↑hoist • Part Meronyms: ↑pulley, ↑pulley block, ↑pulley block, ↑block * * * noun [singular] : a simple machine that is used to help lift heavy objects and that consists of rope and… …   Useful english dictionary

  • block pulley — skrysčiai statusas T sritis fizika atitikmenys: angl. assembly pulley; block pulley; polyspast vok. Flaschenzug, m; Rollenzug, m rus. полиспаст, m; тали pranc. palan, m …   Fizikos terminų žodynas

  • block and tackle — noun a lifting mechanism consisting of ropes, a pulley block, and a hook …   English new terms dictionary

  • Block — (bl[o^]k), n. [OE. blok; cf. F. bloc (fr. OHG.), D. & Dan. blok, Sw. & G. block, OHG. bloch. There is also an OHG. bloch, biloh; bi by + the same root as that of E. lock. Cf. {Block}, v. t., {Blockade}, and see {Lock}.] [1913 Webster] 1. A piece… …   The Collaborative International Dictionary of English

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