A circular saw or a buzz saw , is a power- saw using a toothed or abrasive disc or blade to cut different materials using a rotary motion spinning around an arbor . A hole saw and ring saw also use a rotary motion but are different from a circular saw. Circular saws may also be loosely used for the blade itself. Circular saws were invented in the late 18th century and were in common use in sawmills in the United States by the middle of the 19th century.
93-405: A circular saw is a tool for cutting many materials such as wood , masonry , plastic , or metal and may be hand-held or mounted to a machine. In woodworking the term "circular saw" refers specifically to the hand-held type and the table saw and chop saw are other common forms of circular saws. "Skilsaw" and "Skil saw" have become generic trademarks for conventional hand-held circular saws in
186-418: 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 beveled 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 are made in varying pitch and gauge; the pitch of a chain is defined as half of
279-537: A two-stroke single-cylinder gasoline (petrol) internal combustion engine (usually with a cylinder volume of 30 to 120 cm ) or an electric motor driven by a battery or electric power cord. In a petrol chainsaw, fuel is generally supplied to the engine by a carburetor at the intake. Two-stroke engines have been preferred for chainsaws due to their higher power-to-weight ratio and simplicity. Hydraulic power may be used for chainsaws for underwater use. To allow use in any orientation, modern gas chainsaws use
372-500: A "Birth Choice tool": The tool encourages women to consider out-of-hospital settings where appropriate, and the idea of a "toolkit" is used by the International Labour Organization to describe a set of processes applicable to improving global labour relations . A telephone is a communication tool that interfaces between two people engaged in conversation at one level. It also interfaces between each user and
465-492: A 2010 study suggests the hominin species Australopithecus afarensis ate meat by carving animal carcasses with stone implements. This finding pushes back the earliest known use of stone tools among hominins to about 3.4 million years ago. Finds of actual tools date back at least 2.6 million years in Ethiopia . One of the earliest distinguishable stone tool forms is the hand axe . Up until recently, weapons found in digs were
558-647: A change in the environment, thereby facilitating one's achievement of a target goal. Anthropologists believe that the use of tools was an important step in the evolution of mankind . Because tools are used extensively by both humans (Homo sapiens) and wild chimpanzees , it is widely assumed that the first routine use of tools took place prior to the divergence between the two ape species. These early tools, however, were likely made of perishable materials such as sticks, or consisted of unmodified stones that cannot be distinguished from other stones as tools. Stone artifacts date back to about 2.5 million years ago. However,
651-469: A cheap tool could be used to occupy the place of a missing mechanical part. A window roller in a car could be replaced with pliers . A transmission shifter or ignition switch would be able to be replaced with a screwdriver. Again, these would be considered tools that are being used for their unintended purposes, substitution as makeshift. Tools such as a rotary tool would be considered the substitution "by-design", or "multi-purpose". This class of tools allows
744-672: A circular saw lends itself to cutting hard materials like concrete, asphalt, metal, tile, brick, and stone with an abrasive saw such as a tile saw . Diamond blades and cut off wheels are commonly used in these applications. Tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools , only human beings, whose use of stone tools dates back hundreds of millennia, have been observed using tools to make other tools. Early human tools, made of such materials as stone , bone , and wood , were used for
837-464: A cut is complete. The chainsaw operator may be trapped or crushed. Similarly, timber falling in an unplanned direction may harm the operator or other workers, or an operator working at a height may fall or be injured by falling timber. Like other hand-held machinery, the operation of chainsaws can cause vibration white finger , tinnitus , or industrial deafness . These symptoms were very common before vibration dampening using rubber or steel spring
930-443: A diaphragm carburetor, which draws fuel from the tank using the alternating pressure differential within the crankcase. Early engines used carburetors with gravity fed float chambers , which caused the engine to stall when tilted. The carburetor may need to be adjusted to maintain an appropriate idle speed and air-fuel ratio , such as when moving to a higher/lower altitude or as the air filter clogs. Carburetors are adjusted either by
1023-611: A diverse array of objects and materials, many of which are specifically chosen by certain birds for their unique qualities. Woodpecker finches insert twigs into trees in order to catch or impale larvae. Parrots may use tools to wedge nuts so that they can crack open the outer shell of nuts without launching away the inner contents. Some birds take advantage of human activity, such as carrion crows in Japan, which drop nuts in front of cars to crack them open. Several species of fish use tools to hunt and crack open shellfish, extract food that
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#17328987301031116-474: A drum. On this drum sits either a fixed sprocket or an exchangeable one. The clutch has three jobs: When the engine runs idle (typically 2500–2700 rpm) the chain does not move. When the clutch is engaged and the chain stops in the wood for another reason, it protects the engine. Most importantly, it protects the operator in case of a kickback. Here, the chain brake stops the drum, and the clutch releases immediately. A guide bar, typically an elongated bar with
1209-431: A frame, blade, mandrel, cradle, and power source. The cradle is a tilting or sliding guide that holds logs during the cutting process. Certain cordwood saws are run from a belt from a farm tractor power takeoff pulley. Others, mounted on a tractor's three-point hitch, connect to the rear power takeoff shaft. Self-powered models are equipped with small gasoline engines or even large electric motors as power sources. The mandrel
1302-511: A guide frame was granted to Samuel J. Bens of San Francisco on January 17, 1905, his intent being to fell giant redwoods. The first portable chainsaw was developed and patented in 1918 by Canadian millwright James Shand. After he allowed his rights to lapse in 1930, his invention was further developed by what became the German company Festo in 1933. The company, now operating as Festool , produces portable power tools. Other important contributors to
1395-532: A localized or isolated manner within certain unique primate cultures , being transmitted and practiced among socially connected primates through cultural learning . Many famous researchers, such as Charles Darwin in his book The Descent of Man , mentioned tool-use in monkeys (such as baboons ). Among other mammals , both wild and captive elephants are known to create tools using their trunks and feet, mainly for swatting flies, scratching, plugging up waterholes that they have dug (to close them up again so
1488-682: A major expansion in their use in Ancient Greece and Ancient Rome with the systematic employment of new energy sources, especially waterwheels . Their use expanded through the Dark Ages with the addition of windmills . Machine tools occasioned a surge in producing new tools in the Industrial Revolution . Pre-industrial machinery was built by various craftsmen— millwrights built water and windmills, carpenters made wooden framing, and smiths and turners made metal parts. Wooden components had
1581-411: A round end of wear-resistant alloy steel typically 40 to 90 cm (16 to 36 in) in length, is used. 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: The lower part of
1674-491: A sawmill rips (cuts with the grain) a cordwood saw crosscuts (cuts across the grain). Cordwood saws can have a blade from 20 inches (510 mm) to more than 36 inches (910 mm) diameter depending on the power source and intended purpose. Cordwood saws are used to cut logs and slabs (sawmill waste) into firewood . The cubic meter and Cord (unit) are common measurements of standing timber (by estimation) or rough logs. "Cordwood" means unsplit logs 4 feet (1.2 m) long. In
1767-468: A smaller wound and protect the adjacent muscles, nerves, and veins. While symphysiotomy had too many complications for most obstetricians, Jeffray's ideas about the excision of the ends of bones became more accepted, especially after the widespread adoption of anaesthetics. For much of the 19th century the chainsaw was a useful surgical instrument, but it was superseded in 1894 by the Gigli twisted-wire saw , which
1860-762: 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 chainsaw and skidder crews have been replaced by the feller buncher and harvester . Chainsaws have almost entirely replaced simple man-powered saws in forestry. They are made in many sizes, from small electric saws intended for home and garden use, to large "lumberjack" saws. Members of military engineer units are trained to use chainsaws, as are firefighters to fight forest fires and to ventilate structure fires. Three main types of chainsaw sharpeners are used: handheld file, electric chainsaw, and bar-mounted. The first electric chainsaw
1953-455: Is "makeshift" when human ingenuity comes into play and a tool is used for an unintended purpose, such as using a long screwdriver to separate a cars control arm from a ball joint, instead of using a tuning fork. In many cases, the designed secondary functions of tools are not widely known. For example, many wood-cutting hand saws integrate a square by incorporating a specially-shaped handle, that allows 90° and 45° angles to be marked by aligning
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#17328987301032046-399: Is a common source of damage to chainsaws, and tends to lead to rapid wear of the bar, or the chain seizing or coming off the bar. In addition to being quite thick, chain oil is particularly sticky (due to " tackifier " additives) to reduce the amount thrown off the chain. Although motor oil is a common emergency substitute, it is lost even faster, so leaves the chain under-lubricated. The oil
2139-518: Is a motto of some importance for workers who cannot practically carry every specialized tool to the location of every work task, such as a carpenter who does not necessarily work in a shop all day and needs to do jobs in a customer's house. Tool substitution may be divided broadly into two classes: substitution "by-design", or "multi-purpose", and substitution as makeshift. Substitution "by-design" would be tools that are designed specifically to accomplish multiple tasks using only that one tool. Substitution
2232-532: Is a portable handheld power saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. Modern chainsaws are typically gasoline or electric and are used in activities such as tree felling , limbing , bucking , pruning , cutting firebreaks in wildland fire suppression , harvesting of firewood , for use in chainsaw art and chainsaw mills , for cutting concrete, and cutting ice. Precursors to modern chainsaws were first used in surgery, with patents for wood chainsaws beginning in
2325-672: Is a shaft and set of bearings that support and transfer power to the blade. The frame is a structure that supports the cradle and blade at a convenient working height. Cordwood saws were once very popular in rural America. They were used to cut smaller wood into firewood in an era when hand powered saws were the only other option. Logs too large for a cordwood saw were still cut by hand. Chainsaws have largely replaced cordwood saws for firewood preparation today. Still, some commercial firewood processors and others use cordwood saws to save wear and tear on their chainsaws. Most people consider cordwood saws unsafe and outdated technology. In woodworking
2418-411: Is adjusted so that it neither binds on nor comes loose from the guide bar. The tensioner for doing so is either operated by turning a screw or a manual wheel. The tensioner is either in a lateral position underneath the exhaust or integrated into the clutch cover. Lateral tensioners have the advantage that the clutch cover is easier to mount, but the disadvantage that it is more difficult to reach nearby
2511-450: Is for example a combination of a measuring tool (the clock) and a perception tool (the alarm). This enables the alarm-clock to be a tool that falls outside of all the categories mentioned above. There is some debate on whether to consider protective gear items as tools, because they do not directly help perform work, just protect the worker like ordinary clothing. They do meet the general definition of tools and in many cases are necessary for
2604-483: Is made with stone arches and lined with waterproof concrete. The earliest evidence of water wheels and watermills date back to the ancient Near East in the 4th century BC, specifically in the Persian Empire before 350 BC, in the regions of Mesopotamia (Iraq) and Persia (Iran). This pioneering use of water power constituted perhaps the first use of mechanical energy . Mechanical devices experienced
2697-430: Is normally lubricated for life. Most modern gasoline-operated saws today require a fuel mix of 2% (1:50). Gasoline that contains ethanol can result in problems for the equipment because ethanol dissolves plastic, rubber, and other material. This leads to problems, especially on older equipment. A workaround for this problem is to run fresh fuel only and run the saw dry at the end of the work. Separate chain oil or bar oil
2790-545: Is out of reach, or clear an area for nesting. Among cephalopods (and perhaps uniquely or to an extent unobserved among invertebrates ), octopuses are known to use tools relatively frequently, such as gathering coconut shells to create a shelter or using rocks to create barriers. By extension, concepts which support systematic or investigative thought are often referred to as "tools", for example Vanessa Dye refers to "tools of reflection" and "tools to help sharpen your professional practice" for trainee teachers, illustrating
2883-515: Is pumped from a small pump to a hole in the bar. From there, the lower ends of each chain drive link take a portion of the oil into the gauge towards the bar nose. The pump outlet and bar hole must be aligned. Since the bar is moving out and inwards depending on the chain length, the oil outlet on the saw side has a banana-style long shape. Chains must be kept sharp to perform well. They become blunt rapidly if they touch soil, metal, or stones. When blunt, they tend to produce powdery sawdust, rather than
Circular saw - Misplaced Pages Continue
2976-407: Is pumped, typically each tank filling to keep the nose sprocket well lubricated. Here, one or two bolts from the saw run through. The clutch cover is put on top of the bar and it is secured through these bolts. The number of bolts is determined by the size of the saw. Different bar types are available: Usually, each segment in a chain (which is constructed from riveted metal sections similar to
3069-459: Is used for the lubrication of the bar and chain on all types of chainsaws. The chain oil is depleted quickly because it tends to be thrown off by chain centrifugal force , and it is soaked up by sawdust. On two-stroke chainsaws, the chain oil reservoir is usually filled up at the same time as refueling. The reservoir is normally large enough to provide sufficient chain oil between refueling. Lack of chain oil, or using an oil of incorrect viscosity ,
3162-426: The Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of human labor . By extension, concepts that support systematic or investigative thought are often referred to as "tools" or "toolkits". While a common-sense understanding of
3255-903: The Michel Electric Handsaw Company , with the sole purpose of manufacturing and marketing the saw invented by Michel. The company later renamed itself Skilsaw Inc. Portable circular saws are often still called Skilsaws or Skil saws. Its successor is still sold by Skil as the model 77. To get around the Skil patents, Art Emmons of Porter-Cable invented the direct-drive sidewinder saw in 1928. Recently smaller cordless circular saws with rechargeable batteries have become popular. Cold saw machines are circular saws that are used in many metal cutting operations. The saw blades used are quite large in diameter and operate at low rotational speeds, and linear feeds. There are three common types of blades used in circular saws; solid-tooth, segmental tooth, and
3348-640: The Swiss Army knife represents one of the earliest examples. Other tools have a primary purpose but also incorporate other functionality – for example, lineman's pliers incorporate a gripper and cutter and are often used as a hammer; and some hand saws incorporate a square in the right-angle between the blade's dull edge and the saw's handle. This would also be the category of "multi-purpose" tools, since they are also multiple tools in one (multi-use and multi-purpose can be used interchangeably – compare hand axe ). These types of tools were specifically made to catch
3441-466: The United States of America. Circular saw blades are specially designed for each particular material they are intended to cut and in cutting wood are specifically designed for making rip-cuts , cross-cuts, or a combination of both. Circular saws are commonly powered by electricity, but may be powered by a gasoline engine or a hydraulic motor which allows it to be fastened to heavy equipment, eliminating
3534-449: The appropriate part of the handle with an edge, and scribing along the back edge of the saw. The latter is illustrated by the saying "All tools can be used as hammers". Nearly all tools can be used to function as a hammer, even though few tools are intentionally designed for it and even fewer work as well as the original. Tools are often used to substitute for many mechanical apparatuses, especially in older mechanical devices. In many cases
3627-401: 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,
3720-460: The blade strikes the material, it makes a small chip. The teeth guide the chip out of the workpiece, preventing it from binding the blade. In addition to hand-held circular saws (see below), different saws that use circular saw blades include: Originally, circular saws in mills had smaller blades and were used to resaw lumber after it passed through an "up and down" (muley or sash) saw leaving both vertical and circular saw marks on different sides of
3813-447: The carbide inserted-tooth. The circular saw is typically fed into the workpiece horizontally, and as the saw advances into the material, it severs the material by producing narrow slots. The material is usually held in place during the cutting operation by means of a vise. The chips produced by cutting are carried away from the material by both the teeth of the blade as well as the coolant or other cutting fluid used. The rotary motion of
Circular saw - Misplaced Pages Continue
3906-404: The chain breaks during operation due to poor maintenance or attempting to cut inappropriate materials. Gasoline-powered chainsaws expose operators to harmful carbon monoxide gas, especially indoors or in partially enclosed outdoor areas. Drop starting, or turning on a chainsaw by dropping it with one hand while pulling the starting cord with the other, is a safety violation in most states in
3999-422: The chain might derail. The underside of each link features a small, metal finger called a "drive link", which locates the chain on the bar, helps to carry lubricating oil around the bar, and engages with the engine's drive sprocket inside the body of the saw. The engine drives the chain around the track by a centrifugal clutch, engaging the chain as engine speed increases under power, but allowing it to stop as
4092-447: The chain runs in the gauge. Here, the lubrication oil is pulled by the chain to the nose. This is basically the thickness of the drive links. The end of the saw power head has two oil holes, one on each side. These holes must match with the outlet of the oil pump. The pump sends the oil through the hole in the lower part of the gauge. Saw bar producers provide a large variety of bars matching different saws. Through this hole, grease
4185-535: The communication network at another level. It is in the domain of media and communications technology that a counter-intuitive aspect of our relationships with our tools first began to gain popular recognition. John M. Culkin famously said, "We shape our tools and thereafter our tools shape us". One set of scholars expanded on this to say: "Humans create inspiring and empowering technologies but also are influenced, augmented, manipulated, and even imprisoned by technology". Chainsaw A chainsaw (or chain saw )
4278-409: The completion of the work. Personal protective equipment includes such items as gloves , safety glasses , ear defenders and biohazard suits. Often, by design or coincidence, a tool may share key functional attributes with one or more other tools. In this case, some tools can substitute for other tools, either as a makeshift solution or as a matter of practical efficiency. "One tool does it all"
4371-455: The connection between physical and conceptual tools by quoting the French scientist Claude Bernaud : we must change [our ideas] when they have served their purpose, as we change a blunt lancet that we have used long enough. Similarly, a decision-making process "developed to help women and their partners make confident and informed decisions when planning where to give birth" is described as
4464-549: The definition of what constitutes a tool and therefore which behaviours can be considered true examples of tool use. Observation has confirmed that a number of species can use tools including monkeys , apes , elephants , several birds, and sea otters . Now the unique relationship of humans with tools is considered to be that we are the only species that uses tools to make other tools. Primates are well known for using tools for hunting or gathering food and water, cover for rain, and self-defense. Chimpanzees have often been
4557-543: The design was invented, logs were sawn by hand using a pit saw or using powered saws in a sawmill using an up-and-down saw with a reciprocating motion . The rotary nature of the circular saw requires more power to operate but cuts faster because the teeth are in constant motion. The sound of the circular saw is different from the sound of an up-and-down saw and earned it the nickname buzz-saw . Sawmills first used smaller diameter circular saws to resaw dimension lumber such as lath and wall studs and for edging boards. As
4650-407: The development of several machine tools . They have their origins in the tools developed in the 18th century by makers of clocks and watches and scientific instrument makers to enable them to batch-produce small mechanisms. Before the advent of machine tools, metal was worked manually using the basic hand tools of hammers, files, scrapers, saws, and chisels. Consequently, the use of metal machine parts
4743-627: The disadvantage of changing dimensions with temperature and humidity, and the various joints tended to rack (work loose) over time. As the Industrial Revolution progressed, machines with metal parts and frames became more common. Other important uses of metal parts were in firearms and threaded fasteners, such as machine screws, bolts, and nuts. There was also the need for precision in making parts. Precision would allow better working machinery, interchangeability of parts, and standardization of threaded fasteners. The demand for metal parts led to
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#17328987301034836-467: The early centuries of recorded history, but archaeological evidence can provide dates of development and use. Several of the six classic simple machines ( wheel and axle , lever , pulley , inclined plane , wedge , and screw ) were invented in Mesopotamia . The wheel and axle mechanism first appeared with the potter's wheel , invented in what is now Iraq during the 5th millennium BC. This led to
4929-457: 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. One of the earliest patents for an "endless chain saw" comprising a chain of links carrying saw teeth was granted to Frederick L. Magaw of Flatlands, New York in 1883, apparently for the purpose of producing boards by stretching the chain between grooved drums. A later patent incorporating
5022-480: The engine speed slows to idle speed. Consistent improvement to overall chainsaw design, including adding safety features , has taken place over the years. These include chain-brake systems, better chain design, and lighter, more ergonomic saws, including fatigue-reducing antivibration systems. As chainsaw carving has become more popular, manufacturers are making special short, narrow-tipped bars (called "quarter-tipped" "nickel-tipped", or "dime-tipped" bars, based on
5115-444: The eye of many different craftsman who traveled to do their work. To these workers these types of tools were revolutionary because they were one tool or one device that could do several different things. With this new revolution of tools, the traveling craftsman would not have to carry so many tools with them to job sites, in that their space would be limited to the vehicle or to the beast of burden they were driving. Multi-use tools solve
5208-742: The forerunner of Pioneer Saws Ltd and part of Outboard Marine Corporation , the oldest manufacturer of chainsaws in North America. In 1944, Claude Poulan was supervising German prisoners cutting pulpwood in East Texas. Poulan used an old truck fender and fashioned it into a curved piece used to guide the chain. The "bow guide" now allowed the chainsaw to be used by a single operator. McCulloch in North America started to produce chainsaws in 1948. 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
5301-413: The idea of a saw "with joints like the chain of a watch" independently very soon after Park's original 1782 publication, but that he was not able to have it produced until 1790, after which it was used in the anatomy lab and occasionally lent out to surgeons. Park and Moreau described successful excision of diseased joints, particularly the knee and elbow, and Jeffray explained that the chainsaw would allow
5394-461: The invention of the wheeled vehicle in Mesopotamia during the early 4th millennium BC. The lever was used in the shadoof water-lifting device, the first crane machine, which appeared in Mesopotamia c. 3000 BC , and then in ancient Egyptian technology c. 2000 BC . The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC. The screw ,
5487-469: The large forces involved in the work, from the fast-moving, sharp chain, or the vibration and noise of the machinery. A common accident arises from "kickback" when a chain tooth at the tip of the guide bar catches on wood without cutting through it. This throws the bar (with its moving chain) in an upward arc toward the operator, which can cause serious injury or even death. Another dangerous situation occurs when heavy timber begins to fall or shift before
5580-484: The last of the simple machines to be invented, first appeared in Mesopotamia during the Neo-Assyrian period (911–609 BC). The Assyrian King Sennacherib (704–681 BC) claims to have invented automatic sluices and to have been the first to use water screw pumps , of up to 30 tons weight, which were cast using two-part clay molds rather than by the ' lost wax ' process. The Jerwan Aqueduct ( c. 688 BC)
5673-510: The late 19th century. A chainsaw comprises an engine, a drive mechanism, a guide bar, a cutting chain, a tensioning mechanism, and safety features. Various safety practices and working techniques are used with chainsaws. A "flexible saw", consisting of a fine serrated link chain held between two wooden handles, was pioneered in the late 18th century ( c. 1783 –1785) by two Scottish doctors, John Aitken and James Jeffray , for symphysiotomy and excision of diseased bone, respectively. It
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#17328987301035766-422: The length spanned by any three consecutive rivets (e.g., 8 mm, 0.325 inch), while the gauge is the thickness of the drive link where it fits into the guide bar (e.g., 1.5 mm, 0.05 inch). The conventional "full complement" chain has one tooth for every two drive links. "Full skip" chain has one tooth for every three drive links. Built into each tooth is a depth gauge or "raker", which rides ahead of
5859-407: The longer, clean shavings characteristic of a sharp chain; a sharp saw also needs very little force from the operator to push it into the cut. Specially-hardened chains (made with tungsten carbide ) are used for applications where the soil is likely to contaminate the cut, such as for cutting through roots . A clear sign of a blunt chain is the vibrations of the saw. A sharp chain pulls itself into
5952-479: The meaning of tool is widespread, several formal definitions have been proposed. In 1981, Benjamin Beck published a widely used definition of tool use. This has been modified to: The external employment of an unattached or manipulable attached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself, when the user holds and directly manipulates
6045-524: The modern chainsaw are Joseph Buford Cox and Andreas Stihl ; the latter patented and developed an electric chainsaw for use on bucking sites in 1926 and a gasoline-powered chainsaw in 1929, and founded a company to mass-produce them. In 1927, 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 chainsaws to North America, so new manufacturers sprang up, including Industrial Engineering Ltd (IEL) in 1939,
6138-655: The most common type, but they faced competition from cordless lithium battery powered chainsaws from the late 2010s onwards. Although most cordless chainsaws are small and suitable only for hedge trimming and tree surgery , Husqvarna and Stihl began manufacturing full size chainsaws for cutting logs during the early 2020s. Battery powered chainsaws should eventually see increased market share in California due to state restrictions planned to take effect in 2024 on gas powered gardening equipment. A chainsaw consists of several parts: Chainsaw engines are traditionally either
6231-421: The motor and the blade. In the type known colloquially as a sidewinder , the blade is mounted directly on the motor 's driveshaft . In a worm-drive saw, the blade is driven by a perpendicularly mounted motor using worm gears , which give higher torque. The worm-drive portable circular saw was invented in 1923 by Edmond Michel. In 1924 Michel formed a partnership with Joseph Sullivan, and together they started
6324-492: The need for a separate energy source. There is evidence for the prehistorical use of circular saws by people of Indus Valley Civilization during the Bronze Age. The same was excavated from the archeological site of Lothal , Gujarat . The modern-day circular saw was invented around the end of the 18th century as a rip-saw to convert logs into lumber in sawmills and various claims have been made as to who invented it. Before
6417-511: The nineteenth and early twentieth centuries, farmers would supply householders in town with cordwood, which would then be re-sawn and split to a length and circumference suitable for woodburning heaters and ranges. Almost all these devices were designed to accept 16-inch (410 mm) sticks, conveniently a piece of cordwood cut into three equal lengths. Once a piece of cordwood had been re-sawn to three 16-inch pieces, it could easily be split to stovewood size with an ax. Most cordwood saws consist of
6510-480: The object of study in regard to their usage of tools, most famously by Jane Goodall ; these animals are closely related to humans. Wild tool-use in other primates, especially among apes and monkeys , is considered relatively common, though its full extent remains poorly documented, as many primates in the wild are mainly only observed distantly or briefly when in their natural environments and living without human influence. Some novel tool-use by primates may arise in
6603-412: The only tools of "early man" that were studied and given importance. Now, more tools are recognized as culturally and historically relevant. As well as hunting, other activities required tools such as preparing food, "...nutting, leatherworking , grain harvesting and woodworking..." Included in this group are "flake stone tools". Tools are the most important items that the ancient humans used to climb to
6696-405: The operator or, in some saws, automatically by an electronic control unit . To prevent vibration induced injury and reduce user fatigue, saws generally have an anti-vibration system to physically decouple the handles from the engine and bar. This is achieved by constructing the saw in two pieces, connected by springs or rubber in the same way an automobile suspension isolates the chassis from
6789-499: The preparation of food , hunting , the manufacture of weapons , and the working of materials to produce clothing and useful artifacts and crafts such as pottery , along with the construction of housing , businesses , infrastructure , and transportation . The development of metalworking made additional types of tools possible. Harnessing energy sources , such as animal power , wind , or steam , allowed increasingly complex tools to produce an even larger range of items, with
6882-427: The problem of having to deal with many different tools. Tool use by animals is a phenomenon in which an animal uses any kind of tool in order to achieve a goal such as acquiring food and water, grooming , defense, communication , recreation or construction . Originally thought to be a skill possessed only by humans , some tool use requires a sophisticated level of cognition. There is considerable discussion about
6975-455: The same piece. These saws made it more efficient to cut small pieces such as lath. After 1813 or 1822 saw mills use large circular saws, up to 3 metres (9.8 ft) in diameter. Large saws demand more power than up-and-down saws and did not become practical for sawing timbers until they were powered by steam engines. They are either left or right-handed, depending on which side of the blade the plank falls away from. Benching determines which hand
7068-451: The saw is. Saws of this size typically have a shear pin hole, off axis, that breaks if the saw is overloaded and allows the saw to spin free. The most common version is the ITCO (insert tooth cut-off) which has replaceable teeth. Sawmill blades are also used as an alternative to a radial arm saw. Cordwood saws, also called buzz saws in some locales, use blade of a similar size to sawmills. Where
7161-549: The shells of prey, as well as for scratching. Corvids (such as crows , ravens and rooks ) are well known for their large brains (among birds ) and tool use. New Caledonian crows are among the only animals that create their own tools. They mainly manufacture probes out of twigs and wood (and sometimes metal wire) to catch or impale larvae . Tool use in some birds may be best exemplified in nest intricacy. Tailorbirds manufacture 'pouches' to make their nests in. Some birds, such as weaver birds , build complex nests utilizing
7254-417: The size of their tips). Some chainsaws are built specifically for carving applications. Echo sponsors a carving series. Today's chainsaws have multiple safety features to protect the operator. These include: ‹The template How-to is being considered for merging .› Two-stroke chainsaws require about 2–5% of oil in the fuel to lubricate the engine, while the motor in electrical chain-saws
7347-419: The technology advanced large diameter saw blades began to be used for the head saws and to cut clapboards . Claims to the invention of the circular saw include: Typically, the material to be cut is securely clamped or held in a vise , and the saw is advanced slowly across it. In variants such as the table saw , the saw is fixed and the material to be cut is slowly moved into the saw blade. As each tooth in
7440-416: The term circular saw is most commonly used to refer to a hand-held, electric circular saw designed for cutting wood, but may be used for cutting other materials with different blades. Circular saws can be either left or right-handed, depending on the side of the blade where the motor sits. A left-handed saw is typically easier to use if held in the right hand, and contrariwise for the right-handed saw, because
7533-476: The tool during or prior to use and is responsible for the proper and effective orientation of the tool. Other, briefer definitions have been proposed: An object carried or maintained for future use. The use of physical objects other than the animal's own body or appendages as a means to extend the physical influence realized by the animal. An object that has been modified to fit a purpose ... [or] An inanimate object that one uses or modifies in some way to cause
7626-411: The tooth and limits the depth of cut, typically to around 0.5 mm (0.025"). Depth gauges are critical to safe chain operation. If left too high, they cause very slow cutting; if filed too low, the chain becomes more prone to kick back. Low depth gauges also cause the saw to vibrate excessively. Vibration is uncomfortable for the operator and is detrimental to the saw. The tension of the cutting chain
7719-530: The top of the food chain ; by inventing tools, they were able to accomplish tasks that human bodies could not, such as using a spear or bow to kill prey , since their teeth were not sharp enough to pierce many animals' skins. "Man the hunter" as the catalyst for Hominin change has been questioned. Based on marks on the bones at archaeological sites, it is now more evident that pre-humans were scavenging off of other predators' carcasses rather than killing their own food. Many tools were made in prehistory or in
7812-402: The use of one tool that has at least two different capabilities. "Multi-purpose" tools are basically multiple tools in one device/tool. Tools such as this are often power tools that come with many different attachments like a rotary tool does, so one could say that a power drill is a "multi-purpose" tool. A multi-tool is a hand tool that incorporates several tools into a single, portable device;
7905-554: The user does not need to lean across the saw to see the cutting line. Blades for cutting wood are almost universally tungsten carbide tipped (TCT), but high-speed steel (HSS) blades are also available. The saw base can be adjusted for depth of cut and can tilt up to 45° and sometimes 50° in relation to the blade. Adjusting the depth of cut helps minimize kickback. Different diameter blades are matched to each saw and are available ranging from 14 to 61 centimetres (5.5–24.0 in). Saws can have two different types of linkages between
7998-519: The water does not evaporate), and reaching food that is out of reach. Many other social mammals particularly have been observed engaging in tool-use. A group of dolphins in Shark Bay uses sea sponges to protect their beaks while foraging. Sea otters will use rocks or other hard objects to dislodge food (such as abalone ) and break open shellfish . Many or most mammals of the order Carnivora have been observed using tools, often to trap or break open
8091-482: The wheels and road. In cold weather, carburetor icing can occur, so many saws have a vent between the cylinders and carburetor which may be opened to allow hot air to pass. Cold temperature can also contribute to vibration-induced injury, and some saws have a small alternator connected to resistive heating elements in the handles and/or carburetor. Typically, a centrifugal clutch and sprocket are used. The centrifugal clutch expands with increasing speed, engaging
8184-485: The wood without pressing on the saw. Since the air intake filter tends to clog up with sawdust, it must be cleaned from time to time but is not a problem during normal operation. Protective clothing is designed to protect operators in the event of a moving chain touching their clothing by snarling the chain and sprocket, by using special synthetic fibers woven into the garment. Despite safety features and protective clothing, injuries can still arise from chainsaw use, from
8277-486: Was illustrated in the second edition of Aitken's Principles of Midwifery, or Puerperal Medicine (1785) in the context of a pelviotomy . In 1806, Jeffray published Cases of the Excision of Carious Joints , which collected a paper previously published by H. Park in 1782 and a translation of an 1803 paper by French physician P. F. Moreau, with additional observations by Park and Jeffray. In it, Jeffray reported having conceived
8370-520: Was introduced. Heated handles are additional help. Newer, lighter, and easier to wield cordless electric chainsaws use brushless motors, which further decrease noise and vibration compared to traditional petroleum-powered models. The risks associated with chainsaw use mean that protective clothing such as chainsaw boots , chaps, and hearing protectors are normally worn while operating them, and many jurisdictions require that operators be certified or licensed to work with chainsaws. Injury can also result if
8463-415: Was invented by Stihl in 1926. Corded chainsaws became available for sale to the public from the 1960s onwards, but these were never as successful commercially as the older gas-powered type due to limited range, dependency upon the presence of an electrical socket , plus the health and safety risk of the blade's proximity to the cable. For most of the early 21st century petrol driven chainsaws remained
8556-491: Was kept to a minimum. Hand methods of production were very laborious and costly and precision was difficult to achieve. With their inherent precision, machine tools enabled the economical production of interchangeable parts . Examples of machine tools include: Advocates of nanotechnology expect a similar surge as tools become microscopic in size. One can classify tools according to their basic functions: Some tools may be combinations of other tools. An alarm-clock
8649-415: Was substantially cheaper to manufacture, and gave a quicker, narrower cut, without risk of breaking and being entrapped in the bone. A precursor of the chainsaw familiar today in the timber industry was another medical instrument developed around 1830, by German precision mechanic and orthopaedist Bernhard Heine . This instrument, the osteotome , had links of a chain carrying small cutting teeth with
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