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Chainsaw - Wikipedia. A chainsaw is a portable, mechanical saw which cuts with a set of teeth attached to a rotating chain that runs along a guide bar. It is used in activities such as tree felling, limbing, bucking, pruning, cutting firebreaks in wildland fire suppression and harvesting of firewood. Chainsaws with specially designed bar and chain combinations have been developed as tools for use in chainsaw art and chainsaw mills. Microsoft Suing Grey Market Distributors Bronx. Specialized chainsaws are used for cutting concrete. Chainsaws are sometimes used for cutting ice, for example for ice sculpture and in Finland for winter swimming. Beatsteaks Say Say Say Free Download.

Someone who uses a saw is a sawyer. History. This instrument, the osteotome, had links of a chain carrying small cutting teeth with the edges set at an angle; the chain was moved around a guiding blade by turning the handle of a sprocket wheel. As the name implies, this was used to cut bone. The chain hand saw, a fine serrated link chain which cut on the concave side, was invented around 1. It was illustrated in Aitken's Principles of Midwifery or Puerperal Medicine (1. Jeffray claimed to have conceived the idea of the chain saw independently about that time but it was 1.

In 1. 80. 6, Jeffray published Cases of the Excision of Carious Joints by H. Moreau with Observations by James Jeffray M. D. In this communication he translated Moreau's paper of 1. Park and Moreau described successful excision of diseased joints, particularly the knee and elbow.

Jeffray explained that the chain saw would allow a smaller wound and protect the adjacent neurovascular bundle. While a heroic concept, symphysiotomy had too many complications for most obstetricians but Jeffray's ideas became accepted, especially after the development of anaesthetics. Mechanised versions of the chain saw were developed but in the later 1. Century, it was superseded in surgery by the Gigli twisted wire saw.

For much of the 1. Bens of San Francisco on January 1. His intent being to fell giant redwoods. The company now operates as Festool producing portable power tools. Other important contributors to the modern chainsaw are Joseph Buford Cox and Andreas Stihl; the latter patented and developed an electrical chainsaw for use on bucking sites in 1. In 1. 92. 7, Emil Lerp, the founder of Dolmar, developed the world's first gasoline- powered chainsaw and mass- produced them. World War II interrupted the supply of German chain saws to North America, so new manufacturers sprang up including Industrial Engineering Ltd (IEL) in 1.

Pioneer Saws. Ltd and part of Outboard Marine Corporation, the oldest manufacturer of chainsaws in North America. The early models were heavy, two- person devices with long bars. Often chainsaws were so heavy that they had wheels like dragsaws. Other outfits used driven lines from a wheeled power unit to drive the cutting bar. After World War II, improvements in aluminum and engine design lightened chainsaws to the point where one person could carry them.

In some areas the skidder (chainsaw) crews have been replaced by the feller buncher and harvester. Chainsaws have almost entirely replaced simple man- powered saws in forestry. They come in many sizes, from small electric saws intended for home and garden use, to large . Members of military engineer units are trained to use chainsaws as are firefighters to fight forest fires and to ventilate structure fires. Construction. Combustion engines today (2. The traditional carburetor needs to be adjusted, i.

Electrically influenced carburetors make all adjustments automatically. These systems are provided by most large chain saw producers. Husqvarna calls its . Many saws offer a Winter and Summer mode of operation. Winter mode applies in temperatures below 0 . In warmer environment the hole is closed and both units are not ventilated with warm air.

To ensure clean air supply to the carburetor, chainsaw producers offer different filters with fine or less fine mesh. In clean surrounding air a less fine filter can be used, in dusty environment the other. The fine filter keeps the air clean to its optimum (i. This leads the engine to die. The engines are designed so that they may be operated in different positions, upside- down or tilted 9. Early engines died when tilting (two man saw from Dolmar, Germany from 1. Drive mechanism. Typically a centrifugal clutch and sprocket.

The centrifugal clutch expands with raising spinning speed towards a drum. On this drum sits either a fixed sprocket or an exchangeable one. The clutch has three jobs to do: When the saw runs idle (typically 2. When the clutch is engaged and the chain stops in the wood or another reason, it protects the engine. Most important it protects the operator in case of a kickback. Here the chain break stops the drum and the clutch releases immediately.

Clutches and drums can be in two positions: either turned outside (Husqvarna) or inside (Stihl). Guide bar. An elongated bar with a round end of wear- resistant alloy steel typically 4. An edge slot guides the cutting chain. Specialized loop- style bars, called bow bars, were also used at one time for bucking logs and clearing brush, although they are now rarely encountered due to increased hazards of operation. All guide bars have some elements for operation: Gauge.

The lower part of the chain runs in the gauge. Here the lubrification oil is pulled by the chain to the nose. This is a very important mechanism. Oil holes. At the end of the saw power head there are two oil holes, one on each side.

These holes must match with the outlet of the oil pump. The pump presses the oil through the hole in the lower part of the gauge. The clutch cover is put on top of the bar and it is secured though this/these bolts. It depends on the size of the saw if one or two bolts are installed. Bar types. There are different bar types available: These bars consist of different layers to reduce the weight of the bar. These bars are solid steel bars intended for professional use.

They have commonly an exchangeable nose since the sprocket at the bar nose wears out faster than the bar. These bars are laminated bars with a small sprocket at the nose. The small nose reduces the kickback effect. Such bars are used on consumer saws. Cutting chain. Usually each segment in this chain (which is constructed from riveted metal sections similar to a bicycle chain, but without rollers) features small sharp cutting teeth. Each tooth takes the form of a folded tab of chromium- plated steel with a sharp angular or curved corner and two cutting edges, one on the top plate and one on the side plate.

Left- handed and right- handed teeth are alternated in the chain. Chains come in varying pitch and gauge; the pitch of a chain is defined as half of the length spanned by any three consecutive rivets (e. Conventional . Built into each tooth is a depth gauge or . Depth gauges are critical to safe chain operation. If left too high they will cause very slow cutting, if filed too low the chain will become more prone to kick back. Low depth gauges will also cause the saw to vibrate excessively.

Vibration is not only uncomfortable for the operator but is also detrimental to the saw. Tensioning mechanism. Some way to adjust the tension in the cutting chain so that it neither binds on nor comes loose from the guide bar. The tensioner is either operated by turning a screw or a manual wheel. The tensioner is either in a lateral position underneath the exhaust or integrated in the clutch cover. The lateral tensioner has the advantage that the clutch cover is easier to mount but the disadvantage that it is more difficult to reach nearby the bar. Tensioners through the clutch cover are easier to operate, but the clutch cover is more difficult to attach.

When turning the screw, a hook in a bar hole moves the bar either out (tensioning) or in, making the chain loose. Tension is right when it can be moved easily by hand and not hanging loose from the bar. When tensioning, hold the bar nose up and pull the bar nuts tight. Otherwise the chain might derail.