Ag2_Dec12.pdf

Power Tool Safety T HE SAYING “An ounce of prevention is worth a pound of cure” applies to safety in agricultural mechanics. Tools and machinery have been developed to save time and do work more accurately. They can be used safely only if they are properly cared for and their operation is underst...

Power Tool Safety T HE SAYING “An ounce of prevention is worth a pound of cure” applies to safety in agricultural mechanics. Tools and machinery have been developed to save time and do work more accurately. They can be used safely only if they are properly cared for and their operation is understood. The danger of ignoring safe work procedures becomes clear when you consider the possible results of neglect—death or a serious injury. Objective: þ Describe the importance of safety and identify general safety practices for power tools. Key Terms: Ñ fibrillation safeguarding safety Using Power Tools Safely THE IMPORTANCE OF SAFETY Safety is protection from injury or loss. It is a major concern for any shop or workplace. Safety requires that tools and equipment be kept in good operating condition, with guards in place at all times. It demands training in safe operating procedures. Most of all, it calls for using good judgment and decision making based on knowledge. Decisions should minimize the potential for accident or injury. The vast majority of accidents are caused by human error and cannot be prevented by mechanical safety devices. Safety guards and other devices provide only part of the protection against accidents. Most accidents result from someone’s thoughtlessness or lack of consider- E-unit: Power Tool Safety Page 1 u AgEdLibrary.com Copyright © by CAERT, Inc. — Reproduction by subscription only. 020099 ation for others. Safety depends on you. You must learn the safety rules that apply to the tools you will be using and the tasks you will be doing. You must help others realize the importance of safe operation of tools and equipment. SAFETY PRACTICES Think! Most accidents are caused by thoughtlessness. When in doubt, ask about the correct procedure. Do not hurry; plan your work so you will have plenty of time to finish. At first, this will be difficult, so allow extra time until you become comfortable estimating time. A hurried worker cannot be a careful worker. Try to plan your work to avoid bottlenecks. Do not disturb others when they are operating tools or equipment. Doing so can distract their focus and cause accidents. Do not start or stop a machine unless you are the operator. The operator must be in full control at all times. Operating a machine is a full-time job requiring the operator's undivided attention. Avoid loud talking and shouting. Unnecessary noise is distracting and can make an operator lose focus, causing an accident. Do not engage in horseplay, scuffling, or pushing while in a work area. Unacceptable behavior can become a hazard and cannot be permitted. Always wear eye protection when operating power tools. Everyone in the work area should wear eye protection. Always clean the shop or work area. Dirt and accumulated junk can create safety hazards. Do not use faulty equipment. Examine a machine or tool for safety hazards before operating it. Any equipment that is not in good operating condition should not be used and should have an “Out of Order” label attached. Report any faulty equipment to your teacher. FIGURE 1. Informational labels and signs should be used wherever needed. Cutting tools must be kept sharp, with handles tight, guards in place, and switches within easy reach. Know the locations of fire extinguishers and how to use the extinguishers. E-unit: Power Tool Safety Page 2 u AgEdLibrary.com Copyright © by CAERT, Inc. — Reproduction by subscription only. 020099 Report all injuries to your instructor, including minor cuts or scrapes. Know the location of the first-aid kit and how to use the items in it. The first-aid kit should be examined regularly to be sure all necessary contents are available. Keep observers at a safe distance from the work area. When using a power tool, securely attach the work to a solid work surface so both hands can be used to control the tool. To prevent accidental starting, avoid FIGURE 2. Always know the location of the first-aid kit. holding a tool with a finger on the switch. Before operating a power tool, have good footing; avoid operating a power tool in an off-balance position. Wear appropriate clothing. Avoid loose-fitting clothing, ties, scarves, or jewelry that can get caught in moving parts. The hazardous moving parts on power tools need to be safeguarded. Safeguarding is a process of reducing contact with moving parts by using mechanical guards or shields. Guards are necessary on belts, gears, shafts, pulleys, sprockets, spindles, fly wheels, chains, and other moving parts. Guards are provided to protect the operator and others. Power tools should never be used when the safety guards have been removed. A portable power saw should be equipped with two guards. The upper blade guard covers the top portion of the saw blade. The retractable lower guard covers the lower portion of the saw blade. The lower guard is retracted as the saw makes a cut and must return to the covering position automatically when the saw blade clears the work. When adjusting power tools or setting machines, always disconnect them from the power source. Disconnect tools when not in use. Also disconnect them before servicing or before changing blades, accessories, or cutters. Electric Power Tools Modern shops and work areas typically use electric power tools and equipment. Be alert to the hazards of electricity when using electric power tools. Among the hazards of electric power tools are burns and shock. Even with only a small amount of current, conditions exist that can result in fibrillation of the heart. Fibrillation is the failure of the heart to create the regular pumping action that sends blood through the circulatory system. Shock can also cause you to fall off a ladder or elevated work surface. Become familiar with the procedure to follow if an electrical failure should occur. Locate the master switch controlling the work-site circuits. Know where and how to turn off the E-unit: Power Tool Safety Page 3 u AgEdLibrary.com Copyright © by CAERT, Inc. — Reproduction by subscription only. 020099 power in an emergency. Use a padlock to lock circuits open when they are being worked on. If a circuit is not locked open, it can be inadvertently closed, causing an accident or injury. To protect you and others from electrical shock, a tool needs to be equipped with a threewire cord with ground, and it needs to be grounded, be double insulated, or be powered by a low-voltage isolation transformer. A three-wire cord contains two current-carrying conductors and a grounding conductor. One end of the grounding conductor connects to the power tool and the other end is grounded through a prong on the plug. Some old wiring systems do not provide a ground and require an adapter to accommodate a two-hole receptacle. Many twohole receptacles do not provide grounding protection. Double insulation is more convenient to use. The user and the tools are protected by the insulation on the conductors and by a tool housing that cannot conduct electricity. Check all electric power tools for frayed or damaged cords, faulty plugs, loose connections, and faulty switches. Check extension cords for exposed wires, faulty plugs, damaged insulation, and loose connections. Avoid letting appliance cords or extension cords run across doorways or other traffic areas, as they may cause someone to trip or be injured. Do not operate electrical equipment near water or in damp areas unless special precautions are used to avoid injury. Do not handle electric cords and switches when your hands are wet. When a heavy load is placed on a power tool, the tool can overheat, causing damage and/or a fire. Check the motor temperature frequently when a heavy load is applied. A motor generally emits a peculiar odor when it overheats. Do not use an appliance cord as a handle. Never pull the electric cord to unplug a tool; pull on the plug, not the cord. Keep cords away from heat, FIGURE 3. Never use tools with frayed or damaged cords. oil, and sharp edges. Wipe cords clean before putting them away. Pneumatic Power Tools Pneumatic power tools, or air tools, are powered by compressed air. Being struck by a tool attachment that has come loose and flown through the air is a hazard that must be guarded E-unit: Power Tool Safety Page 4 u AgEdLibrary.com Copyright © by CAERT, Inc. — Reproduction by subscription only. 020099 against when using an air tool. Eye protection is required, and face protection is recommended. Hearing protection should be used with a noisy air tool. Always check to be sure the tool is connected firmly to the hose. Screens can be set up to protect nearby workers from being struck by flying debris. Compressed air should never be pointed toward anyone. Compressed air can damage eyes, lungs, and ears. Do not use a hose as a handle. Keep hoses away from heat, oil, and sharp edges. Wipe hoses clean before putting them away. Hydraulic Power Tools Hydraulic power tools should be used only with approved fluids. They must retain their operating characteristics at the temperature extremes at which the tools will be used. Do not exceed the safe operating pressure for hoses, valves, and other fittings. All Power Tools The hazards encountered when working with power tools can be lessened by following five general safety rules: 1. Keep all tools in good condition with regular maintenance. 2. Use the right tool for the job. 3. Visually examine each tool for damage before use. 4. Operate a power tool according to the manufacturer’s instructions. 5. Use the correct personal protective equipment. Summary: 2 Safety is protection from injury or loss. It involves proper maintenance of tools, equipment, and facilities. It requires the training of operators and demands their good judgment and decision making based on knowledge. Most accidents in agricultural mechanics can be prevented. The use of personal protective equipment, especially eye protection, is recommended. Keeping the work area clean helps reduce hazards. Tools should be kept in good working condition and their cutting accessories sharp. Unplugging or disconnecting power tools from the power supply when making adjustments or changing cutters is a recommended safety practice. Keeping all guards and safety shields in place is essential. Following safety rules can reduce the opportunity for injury. Safety should be the first priority in agricultural mechanics. E-unit: Power Tool Safety Page 5 u AgEdLibrary.com Copyright © by CAERT, Inc. — Reproduction by subscription only. 020099 Checking Your Knowledge: ´ 1. What causes most agricultural accidents? 2. Describe the procedure to follow if a power tool or piece of equipment is found broken or unsafe. 3. Name two types of hazards commonly associated with the use of electric power tools. 4. Describe how a double-insulated power tool protects the operator. Expanding Your Knowledge: L Create a chart listing the items to be included in a first-aid kit and describing how each item should be used. Web Links: : Occupational Safety & Health Administration http://www.osha.gov Basic Shop Safety Rules http://www.envirosafeshop.com/EnviroSafeShop/shop_safety_rules.htm Agricultural Career Profiles http://www.mycaert.com/career-profiles E-unit: Power Tool Safety Page 6 u AgEdLibrary.com Copyright © by CAERT, Inc. — Reproduction by subscription only. 020099