Longman Dictionary of Contemporary English
The Collaborative International Dictionary
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.
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.
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.
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.]
Apparatus for raising or lowering heavy weights, consisting of a rope and pulley blocks; sometimes, the rope and attachments, as distinct from the block, in which case the full appratus is referred to as a block and tackle.
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Any instruments of action; an apparatus by which an object is moved or operated; gear; as, fishing tackle, hunting tackle; formerly, specifically, weapons. ``She to her tackle fell.''
--Hudibras.Note: In Chaucer, it denotes usually an arrow or arrows.
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(Naut.) The rigging and apparatus of a ship; also, any purchase where more than one block is used.
Fall and tackle. See the Note under Pulley.
Fishing tackle. See under Fishing, a.
Ground tackle (Naut.), anchors, cables, etc.
Gun tackle, the apparatus or appliances for hauling cannon in or out.
Tackle fall, the rope, or rather the end of the rope, of a tackle, to which the power is applied.
Tack tackle (Naut.), a small tackle to pull down the tacks of the principal sails.
Tackle board, Tackle post (Ropemaking), a board, frame, or post, at the end of a ropewalk, for supporting the spindels, or whirls, for twisting the yarns.
Wiktionary
n. 1 A system of two or more pulleys (the tackles) each enclosed by a housing (the block) with a rope or cable threaded between them, usually used to lift or pull heavy loads. 2 (context euphemistic English) human male external genitalia
WordNet
n. pulley blocks with associated rope or cable
Wikipedia
A block and tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift or pull heavy loads.
The pulleys are assembled together to form blocks and then blocks are paired so that one is fixed and one moves with the load. The rope is threaded, or rove, through the pulleys to provide mechanical advantage that amplifies that force applied to the rope.
Hero of Alexandria described cranes formed from assemblies of pulleys in the first century. Illustrated versions of Hero's "book on raising heavy weights" show early block and tackle systems.
Usage examples of "block and tackle".
He marked these depths with charcoal and then, helped by Beppe's augmented crew of fifteen, roped the column, attached a block and tackle, slowly raised it to stand upright on Sangallo's turntable.
He is looking at the dented, rusted torpedo hanging by block and tackle from the rafters.
Hand over frantic hand, six knotty-armed men yanked on each block and tackle rig.
But parting was a sweet pain in the ass when you only had to do it once and he wasn't sure he could get it up again with a block and tackle if Sue had stopped cussing him.
They were trying to rig up a block and tackle, but could not find an intact support beam for the chain.
It came out in a linen closet at the end of the hall, and had been built so that bedding and furniture could be lowered down the hollow center of the stairs by means of a block and tackle.
You might be willing to pay big bucks for a B-2 superstar quarterback, but you will also need lower cost and capable riflemen or destroyers to block and tackle.
Those who had caught sharks had taken them to the shark factory on the other side of the cove where they were hoisted on a block and tackle, their livers removed, their fins cut off and their hides skinned out and their flesh cut into strips for salting.
They divided it into cakes by methods too well known to require description, and these, being sledded to the shore, were rapidly hauled off on to an ice platform, and raised by grappling irons and block and tackle, worked by horses, on to a stack, as surely as so many barrels of flour, and there placed evenly side by side, and row upon row, as if they formed the solid base of an obelisk designed to pierce the clouds.
Boon had the spade, axe and block and tackle all three in his hands.
It was too heavy to be carried up the side, and it took four strong seamen on the block and tackle to lift it to the Golden Bough's deck.