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2/7/23 Machine Guarding IE438. Industrial Safety and Health Week 9 Dr. Majed Moosa 1 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 1 Introduction Possible machinery-related injuries include: • • • • Crushed fingers or hands Amputations...

2/7/23 Machine Guarding IE438. Industrial Safety and Health Week 9 Dr. Majed Moosa 1 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 1 Introduction Possible machinery-related injuries include: • • • • Crushed fingers or hands Amputations Burns Blindness A good rule to remember is: Any machine part, function, or process which may cause injury must be safeguarded. PPT 10-hr. General Industry – Machine Guarding v.03.01.17 2 Created by OTIEC Outreach Resources Workgroup 2 1 2/7/23 Machinery Accidents Examples of how machine accidents can occur: • Reaching-in to “clear” equipment • Not using Lockout/Tagout • Unauthorized persons doing maintenance or using the machines • Missing or loose machine guards PPT 10-hr. General Industry – Machine Guarding v.03.01.17 3 Created by OTIEC Outreach Resources Workgroup 3 Machinery Accidents Amputations: • Unguarded/inadequately safeguarded machinery • Materials handling activities Source: OSHA • Activities involving stationary machines Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 4 Created by OTIEC Outreach Resources Workgroup 4 2 2/7/23 Basic Machinery Parts and Hazards Three fundamental machine areas: • Point of operation • Power transmission device • Operating controls – mechanical or electric power control Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 5 Created by OTIEC Outreach Resources Workgroup 5 Basic Machinery Parts and Hazards Point of operation: • Where work is performed on material • Examples – – – – Cutting Shaping Boring Forming Source: OSHA DTE PPT 10-hr. General Industry – Machine Guarding v.03.01.17 6 Created by OTIEC Outreach Resources Workgroup 6 3 2/7/23 Basic Machinery Parts and Hazards Power transmission device: • Parts that transmit energy to the part of the machine performing work • Examples – – – – – Flywheels Pulleys Belts Connecting rods Couplings – – – – – Cams Spindles Chains Cranks Gears PPT 10-hr. General Industry – Machine Guarding v.03.01.17 7 Created by OTIEC Outreach Resources Workgroup 7 Basic Machinery Parts and Hazards Hazardous motions and actions: • Motions – How the machine part moves – Examples: rotating, in-running nip points, reciprocating, and transversing • Actions – Operation that the machine part performs – Examples: cutting, punching, shearing, bending PPT 10-hr. General Industry – Machine Guarding v.03.01.17 8 Created by OTIEC Outreach Resources Workgroup 8 4 2/7/23 Basic Machinery Parts and Hazards • Rotating parts with hazardous projections Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 9 Created by OTIEC Outreach Resources Workgroup 9 Basic Machinery Parts and Hazards • Common nip points on rotating parts Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 10 Created by OTIEC Outreach Resources Workgroup 10 5 2/7/23 Basic Machinery Parts and Hazards • Nip points between rotating elements and parts with longitudinal motions Source of graphics: OSHA 11 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 11 Basic Machinery Parts and Hazards • Nip points between rotating machine components Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 12 Created by OTIEC Outreach Resources Workgroup 12 6 2/7/23 Basic Machinery Parts and Hazards • Reciprocating motions: – Back-and-forth – Up-and-down Source: OSHA 13 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 13 Basic Machinery Parts and Hazards • Transverse motion – movement in straight, continuous line Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 14 Created by OTIEC Outreach Resources Workgroup 14 7 2/7/23 Basic Machinery Parts and Hazards • Cutting action – may involve rotating, reciprocating, or transverse motion Source: OSHA 15 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 15 Basic Machinery Parts and Hazards • Punching action – power applied to a slide (ram) for purpose of blanking, drawing, or stamping metal or other materials Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 16 Created by OTIEC Outreach Resources Workgroup 16 8 2/7/23 Basic Machinery Parts and Hazards • Shearing action – applying power to a slide or knife in order to trim or shear metal or other materials. Source: OSHA 17 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 17 Basic Machinery Parts and Hazards • Bending action – applying power to draw or stamp metal or other materials Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 18 Created by OTIEC Outreach Resources Workgroup 18 9 2/7/23 Machinery That Requires Guarding Machines that require point of operation guarding: • • • • • • • • • Guillotine cutters Shears Alligator shears Power presses Milling machines Power saws Jointers Portable power tools Forming rolls and calenders Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 19 Created by OTIEC Outreach Resources Workgroup 19 Machinery That Requires Guarding • Exposure of fan blades: – Guard when periphery of blades is less than 7’ above the floor or working level – Guards with openings no larger than ½” Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 20 Created by OTIEC Outreach Resources Workgroup 20 10 2/7/23 Machinery That Requires Guarding • Abrasive wheel machinery: – Adjustable tongue guard to within ¼” of wheel – Work rest with maximum opening of 1/8” – Cover spindle end, nut, flange projections Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 21 Created by OTIEC Outreach Resources Workgroup 21 Machinery That Requires Guarding Revolving barrels, containers, and drums: • Guard by an enclosure which is interlocked with drive mechanism • Guards with openings no larger than ½” Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 22 Created by OTIEC Outreach Resources Workgroup 22 11 2/7/23 Machinery That Requires Guarding Power-transmission apparatus: Unguarded belt and pulley • Shafting, flywheels, pulleys, belts, chain drives, etc. • Less than 7 feet from the floor or working platform must be guarded Source: OSHA 23 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 23 Machinery That Requires Guarding Machinery associated with amputations – examples: 1. Mechanical power presses 2. Power press breaks 3. Powered and nonpowered conveyors 4. Printing presses 5. Roll-forming and roll-bending machines 6. Shearing machines 7. Food slicers 8. Meat grinders 9. Meat-cutting band saws 10. Drill presses 11. Milling machines 12. Grinding machines 13. Slitters Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 24 Created by OTIEC Outreach Resources Workgroup 24 12 2/7/23 Requirements for Safeguards Safeguards must meet these minimum general requirements: • • • • • • Prevent contact Be secured Protect from falling objects Create no new hazards Create no interference Allow safe lubrication Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 25 Created by OTIEC Outreach Resources Workgroup 25 Types of Machine Safe Guards Safeguarding machinery: • Primary methods – Guards – Devices • Ensure employee protection – Properly designed, constructed, and installed – Used and maintained in good operating condition PPT 10-hr. General Industry – Machine Guarding v.03.01.17 26 Created by OTIEC Outreach Resources Workgroup 26 13 2/7/23 Types of Machine Safe Guards • Secondary methods – Probe detection and safety edge devices – Awareness devices – Safeguarding methods • Safe distance • Safe holding • Safe opening – Safe work practices • Safe work procedures • Complementary equipment PPT 10-hr. General Industry – Machine Guarding v.03.01.17 27 Created by OTIEC Outreach Resources Workgroup 27 Types of Machine Safe Guards Guards: • Preferable to other control methods • Provide physical barrier that prevents contact with dangerous machine parts • Four general types – – – – Fixed Interlocked Adjustable Self-adjusting Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 28 Created by OTIEC Outreach Resources Workgroup 28 14 2/7/23 Types of Machine Safe Guards Fixed guard: • Provides a barrier • Permanent part of the machine, preferable to all other types of guards. Source of photos: OSHA 29 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 29 Types of Machine Safe Guards Interlocked guards: • Shuts off or disengages power, stops moving parts, and prevents starting of machine when guard is open • May use electrical, mechanical, hydraulic, or pneumatic power, or combination Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 30 Created by OTIEC Outreach Resources Workgroup 30 15 2/7/23 Types of Machine Safe Guards Adjustable guards: • Shuts off or disengages power • Stops moving parts • Prevents starting of machine when guard is open Source: OSHA 31 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 31 Types of Machine Safe Guards Self-adjusting guards: • Openings of barriers determined by movement of the stock • Places barrier between danger area and operator Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 32 Created by OTIEC Outreach Resources Workgroup 32 16 2/7/23 Types of Machine Safe Guards Devices: • Controls or attachments that prevent inadvertent access by employees to hazardous machine areas • Examples – Presence sensing • Photoelectric • Radiofrequency • Electromechanical – Pullback – Restraint – – – – Safety trip controls Two-hand control Two-hand trip Gate 33 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 33 Types of Machine Safe Guards Presence-sensing devices: • Photoelectric • Radiofrequency • Electromechanical Source: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 34 Created by OTIEC Outreach Resources Workgroup 34 17 2/7/23 Types of Machine Safe Guards Pullback devices: • Utilize a series of cables attached to operator • Automatically withdraws hands from point of operation when slide/ram begins to descend Source: OSHA 35 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 35 Types of Machine Safe Guards Source: OSHA • • Hands in die, feeding Point of operation exposed • Pullback device attached and properly adjusted PPT 10-hr. General Industry – Machine Guarding v.03.01.17 Source: OSHA • • Die closed Hands withdrawn from point of operation by pullback device 36 Created by OTIEC Outreach Resources Workgroup 36 18 2/7/23 Types of Machine Safe Guards Restraint devices: • Utilize cables/straps attached to operator’s hands and a fixed point • No extending/retracting action involved • Hand-feeding tools may be necessary Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 37 Created by OTIEC Outreach Resources Workgroup 37 Types of Machine Safe Guards Safety trip controls: • Deactivates the machine in an emergency situation • Examples – Pressure-sensitive bar – Safety tripod – Safety tripwire • Positioning is critical; must stop machine before body reaches danger area Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 38 Created by OTIEC Outreach Resources Workgroup 38 19 2/7/23 Types of Machine Safe Guards Two-hand controls: • Deactivates the machine in an emergency situation • Pressure-sensitive • Positioning is critical; must stop machine before body reaches danger area Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 39 Created by OTIEC Outreach Resources Workgroup 39 Types of Machine Safe Guards Gate devices: • Moveable barrier that protects operator at point of operation before machine cycle can be started • Must be interlocked so machine cannot begin cycle unless gate guard is in place • Must be closed before machine can function • Types – “A” Gate – “B” Gate PPT 10-hr. General Industry – Machine Guarding v.03.01.17 40 Created by OTIEC Outreach Resources Workgroup 40 20 2/7/23 Types of Machine Safe Guards Gate Open Gate devices: • Moveable barrier that protects operator at point of operation before machine cycle can be started • Must be interlocked so machine cannot begin cycle unless gate guard is in place • Must be closed before machine can function Gate Closed Source of graphics: OSHA 41 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 41 Types of Machine Safe Guards Type “A” Gate Operation Type “B” Gate Operation Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 42 Created by OTIEC Outreach Resources Workgroup 42 21 2/7/23 Additional Safeguarding Location/distance: • The dangerous moving part of a machine must be so positioned that those areas are not accessible or do not present a hazard • Feeding process safeguarded by maintaining safe distance to protect worker • Operator’s controls located safe distance from machine Source: OSHA 43 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 43 Additional Safeguarding Feeding and ejection methods: • Automatic/ semi-automatic feed • Automatic/ semi-automatic ejection Transparent Enclosure Guard Stock Feed Roll Completed Work • Robots Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 44 Created by OTIEC Outreach Resources Workgroup 44 22 2/7/23 Additional Safeguarding Miscellaneous aids: • Awareness barriers • Protective shields • Hand-feeding tools Source of graphics: OSHA PPT 10-hr. General Industry – Machine Guarding v.03.01.17 45 Created by OTIEC Outreach Resources Workgroup 45 Identify the Hazard Unguarded lower blade and arbor end of radial saw. PPT 10-hr. General Industry – Machine Guarding v.03.01.17 46 Created by OTIEC Outreach Resources Workgroup 46 23 2/7/23 Identify the Hazard Guard removed from chain rail exposing pins on the spiked chain and sprocket mechanism. 47 Created by OTIEC Outreach Resources Workgroup PPT 10-hr. General Industry – Machine Guarding v.03.01.17 47 Summary • Safeguards are essential for protecting workers from needless and preventable machinery-related injuries • The point of operation, as well as all parts of the machine that move while the machine is working, must be safeguarded • A good rule to remember is: Any machine part, function, or process which may cause injury must be safeguarded PPT 10-hr. General Industry – Machine Guarding v.03.01.17 48 Created by OTIEC Outreach Resources Workgroup 48 24