block and tackle

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 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:

  • block and tackle — Tackle Tac kle (?; sometimes improperly pronounced ?, especially by seamen), n. [OE. takel, akin to LG. & D. takel, Dan. takkel, Sw. tackel; perhaps akin to E. taw, v. t., or to take.] 1. Apparatus for raising or lowering heavy weights,… …   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 — n [C usually singular] a piece of equipment with wheels and ropes, used for lifting heavy things …   Dictionary of contemporary English

  • block and tackle — noun count usually singular a piece of equipment that consists of wheels and ropes, used for lifting heavy objects …   Usage of the words and phrases in modern English

  • block and tackle — n. an arrangement of one or more pulley blocks, with rope or cables, providing significant mechanical advantage for pulling or hoisting large, heavy objects …   English World dictionary

  • Block and tackle — A block and tackle [ Tackle can be pronEng|ˈteɪkəl in this usage.] is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift or pull heavy loads. TOC Overview Although used in many situations, they are… …   Wikipedia

  • block and tackle — the ropes or chains and blocks used in a hoisting tackle. [1830 40] * * * Combination of pulleys with a rope or cable, commonly used to augment pulling force. Two or more of the pulleys are attached to a fixed block, and the remaining pulleys are …   Universalium

  • 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 and tackle — UK / US noun [countable, usually singular] Word forms block and tackle : singular block and tackle plural blocks and tackles a piece of equipment that consists of wheels and ropes, used for lifting heavy objects …   English dictionary

  • block and tackle — block′ and tack′le n. bui the ropes or chains and blocks used in a hoisting tackle • Etymology: 1830–40 …   From formal English to slang

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