Évaluations - 3, GPA: 3.7
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Facilité d'utilisation
This rule applies also for those compact saws designed for use in confined spaces. Position the chain saw in such a way that your body is clear of the cutting attachment whenever the engine is running. Stand to the left of the plane of the cutting attachment. A Warning! Do not operate your chain saw with the starting throttle lock engaged. Cutting with the starting throttle lock engaged does not permit the operator proper control of the saw or chain speed. Begin cutting with the saw at full throttle, engage the bumper spike firmly in the wood (if possible) and then continue cutting. Always work with the bumper spike so that you have better control of the saw. If you work without the bumper spike saw may pull you forwards suddenly. 9 A • Warning! Never touch a chain with your hand or any part of your body when the engine is running, even when the chain is not rotating. The chain continues to rotate for a short period after the throttle trigger is released. A' • Warning! The muffler and other parts of the engine (e.g. fins of the cylinder, spark plug) become hot during operation and remain hot for a while after stopping the engine. To reduce risk of burns do not touch the muffler and other parts while they are hot. A' > Warning! Do not cut any material other than wood or wooden objects. Use your chain saw for cutting only. It is not designed for prying or shoveling away limbs, roots or other objects. When sawing, make sure that the saw chain does not touch any foreign materials such as rocks, fences, nails and the like. Such objects may be flung off, damage the saw chain or cause the saw to kickback. Do not underbuck freely hanging limbs because the chain may get pinched and cause kickback and loss of control. Take special care when cutting shattered wood because of the risk of injury from slivers being caught and thrown in your direction. Don’t put pressure on the saw when reaching the end of a cut. The pressure may cause the bar and rotating chain to pop out of the cut or kerf ("drop"), go out of control and strike the operator or some other object. If the rotating chain strikes some other object, a reactive force may cause the moving chain to strike the operator. To reduce risk of falls, keep rotating saw chain well clear of harness and lifelines. Check condition of harness, belts and ropes at regular frequent intervals. Always pull the saw out of the cut with the chain running. After finishing a cut, activate the chain brake to lock the chain or shut down the engine before moving the saw to another position in the tree. Reactive forces including kickback A > Warning! Reactive forces may occur any time the chain is rotating. Reactive forces can be dangerous! In any chain saw, the powerful force used to cut wood can be reversed (and work against the operator). If the rotating chain is suddenly stopped by contact with any solid object like a log or branch or is pinched, the reactive forces may occur instantly. These reactive forces may result in loss of control which may, in turn, cause serious or fatal injury. An understanding of the causes of these reactive forces may help you avoid loss of control. The most common reactive forces are - kickback, - pushback, -pull-in. 10 Kickback: Kickback occurs when the chain near the upper quadrant of the bar nose contacts a solid object or is pinched. The reaction of the cutting force of the chain causes a rotational force on the chain saw in the direction opposite to the chain movement. This may fling the bar up and back in an uncontrolled arc mainly in the plane of the bar. Under some circumstances the bar moves towards the operator, who may suffer severe or fatal injury. Kickback may occur when the chain at the nose of the guide bar is pinched unexpectedly, unintentionally contacts solid material in the wood or is incorrectly used to begin a plunge or boring cut. It may also occur during limbing. The greater the force of the kickback reaction, the more difficult it is for the operator to control the saw. Many factors influence the occurrence and force of the kickback reaction. These include chain speed, the speed at which the bar and chain contact the object, the angle of contact, the condition of the chain and other factors. The type of bar and saw chain you use is an important factor in the occurrence and force of the kickback reaction. Some STIHL bar and chain types are designed to reduce kickback forces. STIHL recommends the use of reduced kickback bars and low kickback chains. ANSI B 175.1-1991 chain saw kickback standard Section 5.12 of ANSI standard B 175.1-1991, sets certain performance and design criteria related to chain saw kickback. To comply with section 5.12 of ANSI B 175.1-1991: a) saws with a displacement of less than 3.8 cubic inches - must, in their original condition, meet a 45° computer derived kickback angle when equipped with certain cutting attachments. - and must be equipped with at least two ...