A bellows or pair of bellows is a device constructed to furnish a strong blast of

air The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...

. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtight cavity which can be expanded and contracted by operating the handles, and fitted with a

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

allowing air to fill the cavity when expanded, and with a tube through which the air is forced out in a stream when the cavity is compressed. xford English Dictionary, 2nd ed: bellows/ref> It has many applications, in particular blowing on a fire to supply it with air. English Bellows

The term "bellows" is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight (but not airtight) bag allowing the distance between the

lens A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements ...

and film of a folding photographic camera to be varied is called a

bellows A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtig ...

Etymology

Remscheid - Deutsches Werkzeugmuseum 06 ies

"Bellows" is only used in plural. The

Old English Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th c ...

name for "bellows" was , 'blast-bag', 'blowing-bag'; the prefix was dropped and by the eleventh century the simple , , ('bag') was used. The word is cognate with "

belly Belly may refer to: Anatomy * The abdomen, the part of the body between the pelvis and the thorax; or the stomach ** A beer belly, an overhang of fat above the waist, presumed to be caused by regular beer drinking ** Belly dance * The fleshy, cen ...

". There are similar words in

Old Norse Old Norse, Old Nordic, or Old Scandinavian, is a stage of development of North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants of Scandinavia and their overseas settlemen ...

, Swedish, and Danish and Dutch (blaasbalg), but the derivation is not certain. 'Bellows' appears not to be cognate with the apparently similar Latin .

Metallurgy

Several processes, such as metallurgical iron

smelting Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a ...

and

welding Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature techniques such as bra ...

, require so much heat that they could only be developed after the invention, in antiquity, of the bellows. The bellows are used to deliver additional air to the fuel, raising the rate of combustion and therefore the heat output. Various kinds of bellows are used in metallurgy: * Box bellows were and are traditionally used in East Asia. * Pot bellows were used in ancient Egypt. * Tatara foot bellows from Japan. * Accordion bellows, with the characteristic pleated sides, have been used in Europe for many centuries. * Piston bellows developed in Southeast Asia (probably by the

Austronesian peoples The Austronesian peoples, sometimes referred to as Austronesian-speaking peoples, are a large group of peoples in Taiwan, Maritime Southeast Asia, Micronesia, coastal New Guinea, Island Melanesia, Polynesia, and Madagascar that speak Austro ...

) using the principles of the similarly indigenous

fire piston A fire piston, sometimes called a fire syringe or a slam rod fire starter, is a device of ancient Southeast Asian origin which is used to kindle fire. It uses the principle of the heating of a gas (in this case air) by rapid and adiabatic compress ...

. It led to the independent development of bronze and

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

metallurgy in

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...

. They were present in various Southeast Asian cultures, and the technology was transported to

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

via the

Austronesian expansion The Austronesian peoples, sometimes referred to as Austronesian-speaking peoples, are a large group of peoples in Taiwan, Maritime Southeast Asia, Micronesia, coastal New Guinea, Island Melanesia, Polynesia, and Madagascar that speak Austron ...

. :*The technology was later adopted and refined by the Han Chinese into the double-action piston bellows, replacing the native Chinese ox hide pot or drum bellows completely. :* Piston bellows were independently developed in the middle of the 18th century in Europe. *

Metal bellows Metal bellows are elastic vessels that can be compressed when pressure is applied to the outside of the vessel, or extended under vacuum. When the pressure or vacuum is released, the bellows will return to its original shape, provided the material ...

were made to absorb axial movement in a dynamic condition. Often referred to as Axial Dynamics bellows types. Chinese bellows were originally made of ox hide with two pots as described in Mozi's book on military technology in the

Warring States Period The Warring States period () was an era in ancient Chinese history characterized by warfare, as well as bureaucratic and military reforms and consolidation. It followed the Spring and Autumn period and concluded with the Qin wars of conquest ...

(4th century BC). By the

Han Dynasty The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...

, contact with Southeast Asian cultures exposed the Chinese to the bamboo-based piston bellows of Southeast Asians. The acquired piston bellows technology completely replaced the Chinese ox hide bellows that by the

Song Dynasty The Song dynasty (; ; 960–1279) was an imperial dynasty of China that began in 960 and lasted until 1279. The dynasty was founded by Emperor Taizu of Song following his usurpation of the throne of the Later Zhou. The Song conquered the rest ...

, the ox hide bellows were completely extinct. The

Chinese mechanical engineer

Du Shi Du Shi (, d. 38'' Book of Later Han'', vol. 31Crespigny, 183.) was a Chinese hydrologist, inventor, mechanical engineer, metallurgist, and politician of the Eastern Han Dynasty. Du Shi is credited with being the first to apply hydraulic power ( ...

(d. 38) is credited with being the first to use hydraulic power on a double-action piston pumps, through a waterwheel, to operate bellows in metallurgy. His invention was used to operate piston bellows of blast furnaces in order to forge

cast iron Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impur ...

.Needham, Joseph (1986). ''Science and Civilization in China: Volume 4, Part 2''. Taipei: Caves Books, Ltd., p. 370. The

ancient Greeks Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...

ancient Romans In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 ...

, and other civilizations used bellows in bloomery furnaces producing

wrought iron Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which give it a wood-like "grain" ...

. Bellows are also used to send pressurized air in a controlled manner in a fired heater. In modern industry, reciprocating bellows are usually replaced with motorized blowers.

Double-acting piston bellows

Double-acting piston bellows are a type of bellows used by

blacksmith A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such as gates, gr ...

s and smelters to increase the air flow going into the forge, with the property that air is blown out on both strokes of the handle (in contrast to simpler and more common bellows that blow air when the stroke is in one direction and refill the bellows in the other direction). These bellows blow a more constant, and thus stronger, blast than simple bellows.Craddock, Paul T. ''Early Metal Mining and Production''. pp. 183-4. Such bellows existed in China at least since the 5th century BC, when it was invented, and had reached Europe by the 16th century.Temple, Robert K.G. (2007). ''The Genius of China: 3,000 Years of Science, Discovery, and Invention'' (3rd edition). London: André Deutsch, pp. 46-49. . In 240 BC, The ancient Greek inventor

Ctesibius Ctesibius or Ktesibios or Tesibius ( grc-gre, Κτησίβιος; fl. 285–222 BC) was a Greek inventor and mathematician in Alexandria, Ptolemaic Egypt. He wrote the first treatises on the science of compressed air and its uses in pumps (a ...

of Alexandria independently invented a double-action piston bellow used to lift water from one level to another. A piston is enclosed in a rectangular box with a handle coming out one side. The piston edges are covered with feathers, fur, or soft paper to ensure that it is

airtight A hermetic seal is any type of sealing that makes a given object airtight (preventing the passage of air, oxygen, or other gases). The term originally applied to airtight glass containers, but as technology advanced it applied to a larger categor ...

and lubricated. As the piston is pulled, air enters from the far side and the air in the near chamber is compressed and forced into a side chamber, where it flows through the nozzle. Then as it is pushed air enters from the near side and the air in the far chamber flows through the same nozzle.

Double-lung accordion bellows

These have three leaves. The middle leaf is fixed in place. The bottom leaf is moved up and down. The top leaf can move freely and has a weight on it. The bottom and the middle leaves contain valves, the top one does not. Only the top lung is connected to the spout. When the bottom leaf is moved up, air is pumped from the bottom lung into the top lung. At the same time air is leaving the bellows from the top lung through the spout, but at a slower rate. This inflates the top lung. Next the bottom leaf is moved down to pull fresh air into the bellows. While this happens the weight on the top leaf pushes it down, so air keeps leaving through the spout. This design does not increase the amount of air flow going into the forge, but provides a more constant air flow compared to a simple bellows. It also provides more even air flow than two simple bellows pumped alternately or one double-acting piston bellows.

Primitive bellows

The pot bellows in the western room, Area A, looking west

In archaeological ruins of the

Levant The Levant () is an approximate historical geographical term referring to a large area in the Eastern Mediterranean region of Western Asia. In its narrowest sense, which is in use today in archaeology and other cultural contexts, it is ...

, archaeologists have found primitive pot bellows, consisting of a ceramic pot to which a loose leather hide had been attached at the top. Such pot bellows were constructed with a wide rim, so that the hide covering would transmit a maximum amount of air when pumped. The covering was fastened to the pot with a cord under an out-turned rim, or in a groove just below the rim exterior. An opening near the base served to insert a pipe of pen shapable material whose purpose was to direct the air blast to either the furnace or crucible, and which was usually done through the mediation of a tuyère. Tuyères used in conjunction with pot bellows had the function of protecting the ends of perishable tubes leading from the pot into the fire. Places in

Saharan Africa , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...

still make use of primitive pot bellows.

Further applications

Fluid transfer applications

*Bellows are used extensively in hydraulic power circuits and cooling loops. *They are an essential part of

anesthesia machine An anaesthetic machine (British English) or anesthesia machine (American English) is a medical device used to generate and mix a fresh gas flow of medical gases and inhalational anaesthetic agents for the purpose of inducing and maintaining an ...

s. *

Cuckoo clock A cuckoo clock is, typically, a pendulum clock that strikes the hours with a sound like a common cuckoo call and has an automated cuckoo bird that moves with each note. Some move their wings and open and close their beaks while leaning forwards ...

s use bellows to blow air through their

gedackt Gedackt (also spelled gedeckt) is the name of a family of stops in pipe organ building. They are one of the most common types of organ flue pipe. The name stems from the Middle High German word ''gedact'', meaning "capped" or "covered". History ...

(pipes) and imitate the call of the Common Cuckoo bird. * Musical instruments may employ bellows as a substitute or regulator for air pressure provided by the human lungs: ** Accordion,

concertina A concertina is a free-reed musical instrument, like the various accordions and the harmonica. It consists of expanding and contracting bellows, with buttons (or keys) usually on both ends, unlike accordion buttons, which are on the front. The ...

and related instruments **

Reed organ The pump organ is a type of free-reed organ that generates sound as air flows past a vibrating piece of thin metal in a frame. The piece of metal is called a reed. Specific types of pump organ include the reed organ, harmonium, and melodeon. T ...

** Pipe organ **

Musette de cour The musette de cour or baroque musette is a musical instrument of the bagpipe family. Visually, the musette is characterised by the short, cylindrical shuttle-drone and the two chalumeaux. Both the chanters and the drones have a cylindrical b ...

Uilleann Pipes The uilleann pipes ( or , ) are the characteristic national bagpipe of Ireland. Earlier known in English as "union pipes", their current name is a partial translation of the Irish language terms (literally, "pipes of the elbow"), from thei ...

and some other varieties of bagpipes **

Harmonium The pump organ is a type of free-reed organ that generates sound as air flows past a vibrating piece of thin metal in a frame. The piece of metal is called a reed. Specific types of pump organ include the reed organ, harmonium, and melodeon. Th ...

and

melodeon Melodeon may refer to: * Melodeon (accordion), a type of button accordion *Melodeon (organ), a type of 19th-century reed organ *Melodeon (Boston, Massachusetts), a concert hall in 19th-century Boston * Melodeon Records, a U.S. record label in the ...

Portative A portative organ (from the Latin verb , "to carry"), also known during Italian Trecento as the , is a small pipe organ that consists of one rank of flue pipes, sometimes arranged in two rows, to be played while strapped to the performer at a ...

Expansion joint applications

The term "bellows" is used by extension for a number of applications that do not involve air transfer. *Bellows are widely used in industrial and mechanical applications such as rod boots, machinery way covers, lift covers and rail covers to protect rods, bearings and seals from dirt. *Bellows are widely used on

articulated buses An articulated bus, also referred to as a banana bus, bendy bus, tandem bus, vestibule bus, wiggle wagon, stretch bus, or an accordion bus, (either a motor bus or trolleybus) is an articulated vehicle used in public transportation. It is us ...

and

trams A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport ar ...

, to cover the joint where the vehicle bends. *Bellows are used in mechanical aneroids by acting as a precision indicator of pressure levels based on their lateral movement. *Bellows tubing, a type of lightweight, flexible, extensible tubing may be used for delivery of gas or air at near-ambient pressure, as in early aqua-lung designs. *

Folding Fold, folding or foldable may refer to: Arts, entertainment, and media * ''Fold'' (album), the debut release by Australian rock band Epicure * Fold (poker), in the game of poker, to discard one's hand and forfeit interest in the current pot *Abov ...

and

view camera A view camera is a large-format camera in which the lens forms an inverted image on a ground-glass screen directly at the film plane. The image is viewed and then the glass screen is replaced with the film, and thus the film is exposed to exactly ...

s use bellows to exclude light while allowing the lens to be moved relative to the film plane for focusing and, mainly in view cameras, to allow the lens to slide and tilt to control the image ( camera movements). *Piping

expansion joint An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seis ...

: In this application, bellows are formed in series to absorb thermal movement and vibration in piping systems that transport high temperature media such as exhaust gases or steam.

Beekeeping

Bee smokers have bellows attached to the side to provide air to a slow burning fuel. This allows for an increased rate of combustion and a temporarily higher output of smoke on command, something desirable when calming domesticated bees.

Gallery

File:Sealed urethane bellows.JPG, Urethane bellows Image:Blowing_Smoke.jpg, A large bellows creates a mushroom cloud at the Exploratorium in

San Francisco, California San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17th ...

References

Notes

Bibliography

*https://web.archive.org/web/20070919010534/http://www.archaeogate.org/egittologia/article/182/8/mersa-gawasis-red-sea-egypt-unoisiao-and-bu-2003-2004-f.html . *Gernet, Jacques, trans. by J. R. Foster (1972): A History of Chinese Civilization, Cambridge University Press.

External links

* *Moyse - Richard J. and Clarence L. Patent-"Method of Making Bellows"- Jan. 1980 - US4325769-
http://www.google.com/patents/US432576
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