Machine Safeguarding General This dcument will prvide yu a high-level verview n sme best practices pertaining t machine guarding and sample types f guards fund in manufacturing settings. The Main Causes f Machine Related Accidents: Reaching in t clear equipment Nt using Lckut/Tagut Unauthrized persns ding maintenance r using the machines Missing r lse machine guards Where D Hazards Occur? All parts f the machine which mve, such as: Flywheels, pulleys, belts, cuplings, chains, cranks, gears, etc. Feed mechanisms and auxiliary parts f the machine In running nip pints, such as: Traverse Mtin The Primary Requirements fr Safeguards include: Prevent cntact Prevent wrker s bdy r clthing frm cntacting hazardus mving parts. Secure Firmly secured t machine and nt easily remved. Prtect frm falling bjects Ensure that n bjects can fall int mving parts. Create n new hazards Must nt have shear pints, jagged edges r unfinished surfaces. Create n interference Must nt prevent wrker frm perfrming the jb quickly and cmfrtably. Allw safe lubricatin If pssible, be able t lubricate the machine withut remving the safeguards. LC-0908 Rev. 06/16 Page 1
Maximum Permissible Opening Table O -10 Guard Optins Fixed Prvides a barrier as a permanent part f the machine, and is preferable t all ther types f guards. LC-0908 Rev. 06/16 Page 2
Interlcked When this type f guard is pened r remved, the tripping mechanism and/r pwer autmatically shuts ff r disengages, and the machine cannt cycle r be started until the guard is back in place. Adjustable Prvides a barrier which may be adjusted t facilitate a variety f prductin peratins. Self-adjusting Prvides a barrier which mves accrding t the size f the stck entering the danger area. LC-0908 Rev. 06/16 Page 3
Devices Used in Machine Safeguarding Presence sensing Uses physical and nn-physical barriers t detect bjects in the danger zne f a machine. Three General Types Phtelectrical (Optical) uses a light surce Radi Frequency (Capacitance) - Uses a radi beam that is part f the machine cntrl circuit Electrmechanical - Uses a cntact bar r a prbe Pullback LC-0908 Rev. 06/16 Page 4
Utilizes a series f cables attached t the peratr s hands, wrists and/r arms. Primarily used n machines with strking actin. Allws access t the pint f peratin when the slide/ram is up. Withdraws hands when the slide/ram begins t descend. Restraint Uses cables r straps attached t the peratr s hands and a fixed pint. Must be adjusted t let the peratr s hands travel within a predetermined safe area. Hand-feeding tls are ften necessary if the peratin invlves placing material int the danger area. Safety cntrls (tripwire cable, tw-hand cntrl, etc.) Device lcated arund the perimeter f r near the danger area. Operatr must be able t reach the cable t stp the machine. Tw-hand cntrl LC-0908 Rev. 06/16 Page 5
Requires cnstant, cncurrent pressure t activate the machine. The peratr s hands are required t be at a safe lcatin (n cntrl buttns) and at a safe distance frm the danger area while the machine cmpletes its clsing cycle. Gates Mvable barrier device which prtects the peratr at the pint f peratin befre the machine cycle can be started. If the gate des nt fully clse, machine will nt functin. Other items Lcatin/distance Lcate the machine r its dangerus mving parts s that they are nt accessible r d nt present a hazard t a wrker during nrmal peratin. Maintain a safe distance frm the danger area. Prtective Shields These d nt give cmplete prtectin frm machine hazards, but d prvide sme prtectin frm flying particles, splashing cutting ils r clants. Hand Tls LC-0908 Rev. 06/16 Page 6
Used t place and remve stck in the danger area. Nt t be used instead f ther machine safeguards, but as a supplement. Guarding Fan Blades When the periphery f the blades f a fan is less than 7 feet abve the flr r wrking level, the blades must be guarded with a guard having penings n larger than 1/2 inch. Abrasive Wheel Machinery Wrk rests n ffhand grinding machines must be kept adjusted clsely t the wheel with a maximum pening f 1/8-inch t prevent the wrk frm being jammed between the wheel and the rest, which may result in wheel breakage. The distance between the wheel periphery and the adjustable tngue must never exceed 1/4-inch. Machine Safety Respnsibilities Management Ensure all machinery is prperly guarded. Supervisrs Train emplyees n specific guard rules in their areas. Ensure machine guards remain in place and are functinal. Immediately crrect machine guard deficiencies. Emplyees LC-0908 Rev. 06/16 Page 7
D nt remve guards unless machine is lcked and tagged. Reprt machine guard prblems t supervisrs immediately. D nt perate equipment unless guards are in place. Phts used by permissin frm The Natinal Safety Educatin Center, An OSHA Training Institute Educatin Center. Natinal Safety Educatin Center Nrthern Illinis University 590 Garden Rd DeKalb, IL 60115 http://www.nsec.niu.edu/nsec/ LC-0908 Rev. 06/16 Page 8