Wheel to support movement and change of direction of a taut cable
This article is about the mechanical concept and device. For other uses, see Pulley (disambiguation).
Pulley
Pulleys on a ship. In this context, pulleys are normally known as blocks.
Classification
Simple machine
Industry
Construction, transportation
Wheels
1
Axles
1
Sheave without a rope
A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A sheave or pulley wheel is a pulley using an axle supported by a frame or shell (block) to guide a cable or exert force.
A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain.
The earliest evidence of pulleys dates back to Ancient Egypt in the Twelfth Dynasty (1991–1802 BC)[1] and Mesopotamia in the early 2nd millennium BC.[2] In Roman Egypt, Hero of Alexandria (c. 10–70 AD) identified the pulley as one of six simple machines used to lift weights.[3] Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another.[4][5] Plutarch's Parallel Lives recounts a scene where Archimedes proved the effectiveness of compound pulleys and the block-and-tackle system by using one to pull a fully laden ship towards him as if it was gliding through water.[6]
^Arnold, Dieter (1991). Building in Egypt: Pharaonic Stone Masonry. Oxford University Press. p. 71. ISBN 9780195113747.
^Moorey, Peter Roger Stuart (1999). Ancient Mesopotamian Materials and Industries: The Archaeological Evidence. Eisenbrauns. p. 4. ISBN 9781575060422.
^Usher, Abbott Payson (1988). A History of Mechanical Inventions. USA: Courier Dover Publications. p. 98. ISBN 0-486-25593-X.
^Uicker, John; Pennock, Gordon; Shigley, Joseph (2010). Theory of Machines and Mechanisms (4th ed.). Oxford University Press, USA. ISBN 978-0-19-537123-9.
^Paul, Burton (1979). Kinematics and dynamics of planar machinery (illustrated ed.). Prentice-Hall. ISBN 978-0-13-516062-6.
^Rorres, Chris (2017). Archimedes in the 21st Century. Springer International Publishing. p. 71. ISBN 9783319580593.
shaft. A sheave or pulley wheel is a pulley using an axle supported by a frame or shell (block) to guide a cable or exert force. A pulley may have a groove...
pulley design program Helix delta-d Conveyor Pulley to AS1403 Software Pulley Maven, software for designing and analyzing conveyor pulleysPulley manufacturers...
type of CVT uses a V-belt which runs between two variable-diameter pulleys. The pulleys consist of two cone-shaped halves that move together and apart. The...
as A pulleys, are the annular part of the fibrous sheathes of the fingers. Four or five such annular pulleys, together with three cruciate pulleys, form...
the belt forward. The powered pulley is called the drive pulley while the unpowered pulley is called the idler pulley. There are two main industrial...
A differential pulley —also called "Weston differential pulley", sometimes "differential hoist", "chain hoist", or colloquially "chain fall"— is used...
variously as a ceiling clothes airer, laundry airer, pulley airer, laundry rack, or laundry pulley, is a ceiling-mounted mechanism to dry clothes. It is...
is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads. The pulleys are assembled to form blocks...
or main (drive) pulley smaller or making the accessory (driven) pulley larger than the original diameter pulleys. Underdrive pulleys increase engine output...
Sir Joseph Pulley, 1st Baronet, DL (8 September 1822 – 5 August 1901), was an English Liberal politician. Pulley was the son of Joseph Pulley of Bayswater...
pigacia and pigatia. The pigache is also known as the pigage, pulley shoe, pulley toe, or pulley-toe shoe. Less often, Orderic Vitalis's terms of opprobrium...
Natasha Pulley (born 4 December 1988) is a British author. She is best known for her debut novel, The Watchmaker of Filigree Street, which won a Betty...
Emily Ann Pulley (born 14 April 1967) is an American opera soprano. As of 2010, she had performed in more than 150 operas. Pulley earned a Bachelor of...
balance the rotating assembly. The harmonic balancer often serves as a pulley for the accessory drive belts turning the alternator, water pump and other...
Belt Pulley was a U.S.-based magazine dedicated to antique farm tractors of all brands and makes. It published successfully for over 2 decades and was...
Pulley Ridge is a mesophotic coral reef system off the shores of the continental United States. The reef rests on sunken barrier islands and lies 100 miles...
Spencer Kyle Pulley (born April 3, 1993) is a former American football center. He played college football at Vanderbilt. He was signed by the San Diego...
The furcula (Latin for "little fork"; pl.: furculae) or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is formed...
Cleve Andrew Pulley (born May 5, 1951), better known as Andrew Pulley, is an American former politician who ran as Socialist Workers Party (SWP) nominee...
April Pulley Sayre (April 11, 1966 — November 6, 2021) was an American children's book author from the 1990s to 2020s. Before becoming an author, Sayre...
Curtis Pulley (born December 19, 1986) is a former American football quarterback for the Florida A&M University Rattlers. Pulley used to be a quarterback...
multiple pulleys creates mechanical advantage, by having the flexible material looped over several pulleys in turn. Adding more loops and pulleys increases...
A zip-line, zip line, zip-wire, flying fox, or death slide is a pulley suspended on a cable, usually made of stainless steel, mounted on a slope. It is...
Global Information
