Definify.com
Webster 1913 Edition
Pulley
Pul′ley
,Noun.
pl.
Pulleys
(#)
. [F. ); but cf. OE.
poulie
, perhaps of Teutonic origin (cf. Poll
, Verb.
T.
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.
☞ 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 6.
– Block
, Noun.
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
,Verb.
T.
To raise or lift by means of a pulley.
[R.]
Howell.
Webster 1828 Edition
Pulley
PULL'EY
,Noun.
plu.
A small wheel turning on a pin in a block, with a furrow or groove in which runs the rope that turns it.
The pulley is one of the mechanical powers. The word is used also in the general sense of tackle, to denote all parts of the machine for raising weights, of which the pulley forms a part.
Definition 2024
pulley
pulley
English
A fixed pulley assembly
Noun
pulley (plural pulleys)
- One of the simple machines; a wheel with a grooved rim in which a pulled rope or chain will lift an object (more useful when two or more pulleys are used together such that a small force moving through a greater distance can exert a larger force through a smaller distance).
Translations
one of simple machines
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References
- ↑ Skeat, An Etymological Dictionary of the English Language, "pulley".
- ↑ Diez, An Etymological Dictionary of the Romance Languages, "pulley".
- ↑ Century Dictionary and Cyclopedia, "pulley".
See also
- inclined plane
- lever
- polyspast
- block and tackle
- ****
- wedge
- wheel
- Wikipedia article on the simple machines
Verb
pulley (third-person singular simple present pulleys, present participle pulleying, simple past and past participle pulleyed)
- (transitive) To raise or lift by means of a pulley.
- (Can we find and add a quotation of Howell to this entry?)