PULLEYS
Noun
pulleys
plural of pulley
Verb
pulleys
Third-person singular simple present indicative form of pulley
Source: Wiktionary
PULLEY
Pul"ley, n.; pl. Pulleys. Etym: [F. poulie, perhaps of Teutonic
origin (cf. Poll, b. 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.)
Definition: 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.
Pul"ley, b. t.
Definition: To raise or lift by means of a pulley. [R.] Howell.
Source: Webster’s Unabridged Dictionary 1913 Edition