Video Chainsaw
Histori
The origin is disputed, but tools such as saws were made around 1830 by the German orthopedist Bernhard Heine. This instrument, osteotome, has a chain connection that carries a small cutting tooth with its edges arranged at an angle; The chain moves around the guiding blade by turning the sprocket wheel handle. As the name implies, it is used to cut bones. The prototype of a chain known today in the wood industry was pioneered in the late 18th century by two Scottish doctors, John Aitken and James Jeffray, for the symphisiotomy and excision of the respective sick bone. Chainsaws, a chain of fine serrated chains that cut on the sunken side, were found around 1783-1785. It is illustrated in the Aitken Principles of Midwifery or Puerperal Medicine (1785) and used by him in his surgery. Jeffray claimed to have grasped the idea of ​​a chain saw independently of the time, but it was 1790 before he could produce it. In 1806, Jeffray published the Cases of Exile of the Carikeys Alliance by H. Park and PF Moreau with Observations by James Jeffray MD In this communication he translated Moreau's 1803 papers. Park and Moreau described the successful excision of a sore joint, especially the knee and elbow. Jeffray explained that chainsaws would allow smaller cuts and protect neighboring neurovascular bundles. While the concept is heroic, symphysiotomy has too many complications for most obstetricians but Jeffray's idea becomes accepted, especially after the development of anesthesia. The mechanical version of the chainsaw was developed but in the later 19th Century, it was replaced by a Gigli wire sawpack. For much of the 19th century, chainsaws were a useful surgical tool.
The earliest patent for the "endless chain saw" practical (chain saw chain carrying sawtooth and walk in guide frame) was given to Samuel J. Bens of San Francisco on January 17, 1905. His intentions fell into giant redwoods. The first portable saw was developed and patented in 1918 by the Canadian millwright James Shand. After he allowed his right to expire in 1930, his discovery was further developed by what became the German company Festo in 1933. The company now operates as a Festool producing portable power tools. Other important contributors to the modern saws are Joseph Buford Cox and Andreas Stihl; the latter patenting and developing electric saws for use on bucking sites in 1926 and gasoline-powered saws in 1929, and setting up companies to mass-produce. In 1927, Emil Lerp, founder of Dolmar, developed the world's first gasoline-powered saws and mass-produced them.
World War II disrupted the supply of German chainsaws to North America, so new manufacturers emerged including Industrial Engineering Ltd (IEL) in 1947, the pioneer of Pioneer Saws. Ltd. and part of Outboard Marine Corporation, the oldest saw manufacturer in North America.
McCulloch in North America began producing saws in 1948. The initial model was a heavy device, two people with long bars. Often the saws are so heavy that they have wheels like dragsaws. Other clothing uses the driving line of the power unit to drive the cutting rod.
After World War II, improvements to the aluminum and engine design lighten up the chainsaw to the point where one person can carry it. In some areas the skidder crew (saws) have been replaced by loggers and reaper bunches.
Saws almost completely replace the human-powered simple saws in forestry. They come in a variety of sizes, from small electric saws intended for home and garden use, to large "woodcutter" saws. Members of the unit of military engineers are trained to use chainsaws such as firefighters to fight forest fires and to ignite structural fires.
There are three main types of chainsaw sharpeners - Handheld Files, Chain Saws and Installed Bar.
Maps Chainsaw
Construction
Chainsaws consist of several parts:
Engine
The Chainsaw engine is traditionally a two-stroke gasoline engine (usually with a cylinder volume of 30 to 120 cm 3 ) or an electric motor powered by a battery or power cord. Today's combustion engine (2016) is supplied through a traditional carburetor or carburetor that can be electronically adjusted.
Traditional carburetors need to be adjusted, i. e. when operating at high or low altitudes, or their oil-to-gas fuel ratio should be adjusted to run well. Electrically influenced carburetors make all adjustments automatically. This system is provided by most major chainsaw manufacturers. Husqvarna calls "Autotune," and that's generally standard on most 5XX series saws.
To reduce the problem of user fatigue, traditional carburetors can be vibrated (protected from vibration) or they can be heated as well. Many saws offer winter and summer operations. Winter mode applies in temperatures below 0 Â ° C/32 Â ° F where inside the open hole cover leaves warm air to the air filter and carburetor to prevent the ice sheet. In a warmer environment the hole is closed and both units are not ventilated with warm air.
To ensure clean air supply to the carburetor, the saw manufacturer offers different filters with fine fine fine mesh. In the clean air around the filter that is less good can be used, in other dusty environments. Smooth filter keeps the air clean optimally (ie 44 Âμm) but tends to clog. This causes the engine to die.
The machine is designed in such a way that it can be operated in different positions, upside down or tilting 90 degrees. The original machine died when it slanted (two people saw from Dolmar, Germany 1930-1937).
Drive Mechanism
Usually clutch centrifugal and sprocket. The centrifugal clutch expands by raising the rotating speed toward the drum. In this drum there is a fixed or exchangeable sprocket. The clutch has three jobs to do: When the saw is idle (usually 2500-2700 rpm) the chain is not moving. When the clutch is activated and the chain stops in wood or other reasons, it protects the engine. The most important thing is to protect the operator in case of dings. Here, the chain brakes stop the drums and clutches immediately.
The clutch and drums can be in two positions: either changed outside (Husqvarna) or inside (Stihl).
Guidelines
An elongated bar with a rounded end of wear resistant alloy steel is usually 40 to 90 cm (16 to 36 inches) in length. A slot edge guides the cutting chain. A special loop style bar, called a bow bar, is also used at one time for bucking logs and cleaning brushes, although it is now rarely encountered due to increased operating hazards.
All of the guide blades have several elements for the operation:
Gauge
The bottom of the chain goes in the gauge. Here the lubricating oil is pulled by the chain to the nose. This is a very important mechanism.
Oil hole
At the head of the saw saw two oil holes, one on each side. These holes should match the outlet of the oil pump. The pump pumps the oil through the hole at the bottom of the gauge. (See also below)
Saw bar manufacturers provide a wide range of different chainsaw bar matching.
Oil hole in the bridge of the nose
Through this lubricating hole is pumped, usually each tank fills in order to properly lubricate the nose sprocket.
Guide slot
Here one or two screws from the saw are executed. Clutch cover is placed over the bar and secured by this bolt. It depends on the size of the saw if one or two bolts are installed.
Type bar
There are different types of bars available:
- Laminated bars
These blades consist of different layers to reduce the weight of the blade.
- Solid stick
These rods are solid steel bars intended for professional use. They have noses that can be exchanged in general since the sproket on the nose stalks runs out faster than the bar.
- Security bars
These bars are laminated bars with small sprockets in the nose. Small nose reduces the effect of dings. Such blades are used on consumer saws.
Cut chain
Usually every segment in this chain (built from metal parts glued similar to a bicycle chain, but without a roller) has small sharp cutting teeth. Each tooth takes the shape of a folded tab of chrome-plated steel with sharp or sharply curved angles and two sloping edges, one on a plate and one on the side plate. The left and right teeth alternated in the chain. Chains come in a variety of tones and gauges; pitch of the chain is defined as half of the length spanned by three successive rivets (eg, 8 mm, 0.325 inches), while the gauge is the thickness of the drive link in which it fits into the guide bar (eg 1.5 Ã, mm , 0.05 inches). The conventional "complementary" chain has one tooth for every two drive links. The "full jump" chain has one tooth for every three drive links. Built into each tooth is a depth or "rake" gauge that rises in front of the tooth and limits the depth of the wound, usually about 0.5 mm (0.025 ").The depth gauge is essential for safe chain operation If left too high, which is very slow, if too low, the chain will be easier to kick back.The low depth gauge will also cause the churning rudder excessively.Vibe is not only uncomfortable for the operator but also harming the saw.
Mechanism of tensioning
Some ways to adjust the tension in the cutting chain so that it is not tied or apart from the guide bar. Tensioner is operated by rotating the screw or manual wheel. The tensioner is in the lateral position under the exhaust or integrated in the clutch cover.
The lateral tensioner has the advantage that the clutch cover is easier to install but the losses are harder to reach near the bars. Tensioner through the clutch cover is easier to operate, but the clutch cover is more difficult to install.
When turning the screw, the hook inside the bar hole moves the bar out (tensioning) or enter, making the chain loose. Tension is true when it can be moved easily by hand and not hanging off from the bar. When tightening, hold the bridge of the nose up and pull the tight bar. Otherwise, the chain will slip.
The bottom side of each link has a small metal finger called "propulsion link" (also DL) that places the chain in the bar, helps carry the lubricating oil around the bar, and engages with the engine drive sprocket inside the saw body.. The engine moves the chain around the track with a centrifugal clutch, pulling the chain as the engine speed rises below power, but allows it to stop as the engine speed slows to idle speed.
Dramatic improvements, chainsaw security devices and overall design have taken place since the invention of chainsaw, saving many lives and preventing countless serious injuries. These include brake system chains, better chain design and anti-vibration systems.
As chainsaws have become more popular, sawmakers create short, narrow-headed bars specifically for engraving. It's called "quarter tipped," "nickel tipped" or "dime tipped" bar, based on the size of the rounded end. Manufacturer of Chainsaw Echo sponsors engraving series, as well as sculptors such as former Runaways singer Cherie Currie. Some chainsaws such as CV RedMax G3200 are made specifically for carving applications.
Security features
Today's chainsaws show all the safety features to protect carriers. All these features are not 100% guarantee that the operator will not be harmed. The best protection, however, is the experience.
- Chain brake
Brake chain is located in the clutch cover. Here the tension bands around the Clutch drums stop the chain in milliseconds. The chain brake is released by the upper hand by hand or wrist. The brakes are meant to be used in reverse kick moments.
- Chain catcher
The chain catcher is located between the chainsaw and the clutch cover. In most cases, it looks like a hook made from aluminum. This is used to stop the chain when it shifts from the bar and shortens the length of the chain. When damaging the chain swinging from under the saw to the operator. Shorting prevents hitting the operator, but crashing into the rear guard handler.
- The handle of the rear handle
The back handle hold protects the operator's hand when the chain is sliding.
- Chains
Some chains show safety features as safety links such as on a micro chainsaw. This link keeps the saw close to the gap between the two cutting links and lifts the chain when the space on the security link is full of chainsaw chips. It lifts the chain and lets it slower.
Maintenance
The two-step saw requires about 2-5% oil in the fuel to lubricate the engine, while the motor in electric chain saws are usually lubricated for life. Most gas-operated saws today require a fuel mixture of 2% (1:50). Regular gas from most gas stations contains 5 to 10% ethanol which can cause equipment problems. Ethanol dissolves plastic, rubber, and other materials. This causes problems especially on older equipment. A solution to this problem is to run the fuel just and run a dry saw at the end of the job.
Separate oil chains or bar oil is used for bar and chain lubrication on all types of chain saws. Chain oils run out quickly because they tend to be thrown by the power of centrifugal chains, and soaked by sawdust. On a two-stroke saw, the chain oil reservoir is usually filled at the same time as the refueling. Reservoirs are usually large enough to provide sufficient chain oil between refueling. The lack of an oil-chain, or using the wrong viscous oil, is a common source of damage to chainsaws, and tends to lead to rapid wear of bars, or chains snatching or coming from bars. In addition to being fairly thick, the oil chain is very sticky (due to "tackifier" additives) to reduce the amount thrown from the chain. Although motor oil is a common emergency replacement, it loses faster and leaves the chain under-lubricated.
Oil chains can not decompose or degrade. Professionals should use biodegradable oils in Germany by law.
Oil is pumped from a small pump to a hole in the bar. From here the lower end of each chain drive link takes some oil to the gauge to the bridge of the nose. The pump output hole and the bar must be aligned. Since the bar moves outward and inward depending on the length of the chain, the oil outlet on the sight side has a long form of banana style.
The chain must stay sharp for good performance. They become dull quickly if they touch the ground, metal or stone. When blunt, they tend to produce sawdust powder, rather than longer, clean shavings characteristic of sharp chains; a sharp saw also requires a bit of power from the operator to push it into pieces. Hardened special chains (made with tungsten carbide) are used for applications where soils tend to contaminate pieces, such as root cutting.
The clear sign of a blunt chain is the vibration of the saw. A sharp chain pulls itself into the wood without pressing the saw.
The air intake filter tends to be clogged with sawdust. It should be cleaned from time to time, but it does not matter during normal operation.
Security
Despite safety features and protective clothing, injuries can still arise from the use of chainsaws, from the great power involved in the work, from fast-moving sharp chains, or from vibrations and engine noise.
Common accidents arise from bribes , when the chain teeth at the end of the guide bar catch the wood without cutting it. It throws a bar (with a moving chain) in an arc towards an operator that can cause serious injury or even death.
Other dangerous situations occur when heavy timber begins to fall or shifts before cutting is complete - the chainsaw operator may be stuck or destroyed. Similarly, timber falling in the unplanned direction may compromise the operator or other worker, or the operator working at altitude may fall or be injured by the falling timber.
Like other handheld machines, chainsaw operations can cause vibrations of white fingers, tinnitus or industrial deafness. These symptoms are very common when the equipment is not vibrated. In today's equipment there is a damping element (in rubber or spring steel) that lowers this risk. The hot handle is an additional help. New, wireless saws use a brushless motor that further reduces noise and vibration while it's lighter and easier to use than traditional oil-powered models.
The risks associated with the use of chainsaw mean that protective clothing such as sunglasses, saw blades and hearing protectors are commonly used when operating, and many jurisdictions require operators to be certified or licensed to work with chainsaws. Injuries can also occur if the chain is broken during surgery due to poor maintenance or trying to cut off inappropriate materials.
Gasoline powered saws expose carriers to harmful carbon monoxide (CO) gases, especially indoors or in partially closed open areas.
Drop starting, or turning a saw by dropping it with one hand while pulling the cable early with another, is a breach of security in most states in the US. Keeping both hands on the saw for stability is essential for safe use of chainsaws.
The use of safe and effective saws and crosscuts on public land run by the federal government in the United States has been codified since July 19, 2016 in the publication of the Final Directive for the National Saw Program issued by the United States Department of Forestry, the USDA establish training, testing, and certification processes for employees as well as for unpaid volunteers who operate chainsaws on public lands.
The new guidance establishes the Forest Service Manual (FSM) 2358 (PDF) which includes the classification of sawers, their Personal Protective Equipment (APD) and other aspects of training and safety behavior required when operating chainsaws or saws on government-run public land federal.
Working techniques
The Chainsaw Training is designed to provide technical knowledge and job skills to operate the equipment safely.
- Size - It guides and plots a safe cut for the direction of felling, danger zone, and rewind path, before starting the saw. The location of the tree relative to other objects, support, and voltage determines a safe fall, interrupted or if the saw gets stuck. Some factors to consider are: lean and crooked trees, wind direction, branch settings, snow loads, obstacles and damage, rotting tree parts, which may behave unexpectedly when cut. Trees may have to fall in the natural direction if too dangerous or impossible to fall in the desired direction. The goal is to have the tree fall safely to limb and cut the log. The goal is to avoid falling trees to trees or other obstacles.
- Felling - After clearing the base tree bushes for the retreat and the felling direction; logging is done correctly with three major pruning. To control falling, the line-cut should run 1/4 of the diameter of the tree to create a 45-degree slice, which should be 90 degrees in the direction of felling and perfect horizontal. Make the top cut first, then the bottom piece is made to form a directional cut line at the wedge point. A narrow or non-existent hinge will reduce the directional control. From the opposite side of the slice, plan to finish the last cut cutting 1/10 of the tree diameter from the direction cut line. The cutting piece is made horizontally and slightly (1.5-2 inch, 5.1 cm) above the bottom piece. When the hinges are set up properly, the cutting pieces will start falling in the desired direction. A sitback is when a tree moves back in the opposite direction. Placing an incision on the cutting piece can prevent a sitback from pinching the saw.
- Unleash - Work on a highly fallen tree that may be trapped in another tree. Process the maximum voltage location to decide on the safest way to release tension, and a winch may be required in complicated situations. To avoid cutting straight through the tree in tension, one or two cuts in the point of deep enough voltage to reduce tension may be required. After the release of tension, the wound is made outside the bend.
- Limbing - Cut off branches from logs. The operator must be able to achieve the cuts correctly to avoid kickback.
- Bucking - Traverses logs that have been logged into sections. Settings are made to avoid binding of saws in tension change and log compression. Bucking safely starts at the top of the log and then the offside works part, towards the butt end. The offside log falls and allows gravity to help prevent bonding. Watching the scratching movement of the log while cutting, helps indicate the bond. Additional equipment (elevators, bars, wedges and cranes) and special cutting techniques can help prevent bonding.
- Bind - This is when chainsaws are at risk or trapped in log compression. Chainsaw logs are not safe, and should be removed carefully to prevent damage to equipment.
- Tie up - The voltage area at the bottom of the log, the compression above.
- Binding down - The voltage area at the top of the log, compression at the bottom.
- Side bind - Pressure sideways provided on the log.
- End bind - Weight solidifies the entire cross log.
- Brush and cut - This quickly cleans small trees and twigs under 5 inches (13 cm) in diameter. A hand piler can follow to move the debris.
Cutting stones, concrete and brickwork
A special saw can cut concrete, bricks and natural stone. It uses chains similar to ordinary saws, but with sharp edges embedded with sand. They may use gasoline or hydraulic power, and the chain is lubricated with water, due to high friction and to remove stone dust. This machine is used in construction, for example in cutting the inner square hole in the wall or floor, in stone sculpture to remove large pieces of stone during pre-carving, by the fire department to gain access to buildings and in the restoration of buildings and monuments, to remove parts with minimal damage to surrounding structures. The newer concrete saws with 230 volt electric motors have also been developed.
Because the material to be cut is not fibrous, the chances of kickback is much less. Therefore, the most commonly used cutting method is cutting-down, by pushing the tip of the blade into the material. With this method of cutting a square as small as the width of the blade can be achieved. Withdrawals can occur if the blocks shift when almost cut and pinch the blades, but overall the machine is more dangerous than a wooden saw blade.
See also
- Bandsaw
- Chainsaws in popular culture
- Circular saw
- Dragsaw
- Jigsaw
- Portable sling
- Chainsaw
- Small engine
References
External links
- How Chainsaw Works. , Popular Science, August 1951
Source of the article : Wikipedia
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