Subpart O Machine Guarding Subpart O o o
Subpart O Machine Guarding
Subpart O o o o o 1910. 211 1910. 212 1910. 213 1910. 215 1910. 216 1910. 217 1910. 218 1910. 219 Definitions General Requirements for all Machines Woodworking Machinery Abrasive Wheel Machinery Mills and Calendars Mechanical Power Presses Forging Machinery Mechanical Power-Transmission
Basics of machine safeguarding A good rule to remember is: o Any machine part; function; or process which may cause injury must be safeguarded.
Basic areas of safeguarding o The point of operation o Power transmission apparatus o Other moving parts (reciprocating, transverse, or rotating)
Motions o Rotating (including in-running nip points) o Reciprocating o Transverse
Nip points Nip point Nip point
In running nip points on rolls
Nip points A Typical nip points Nip point B Nip point C
Rotating hazards Burr Rotating pulley with spokes and projecting burr on face of pulley Rotating shaft and pulleys with projecting key and set screw Rotating coupling with projecting bolt heads
Pinch points caused by tables Table Bed (stationary)
Guarding table pinch points
Transverse motion of a belt Transverse motion of belt
Safeguarding Guards o Prevent access to the danger areas Devices o Control access to the point of operation
Actions o o Cutting Punching Shearing Bending
Different actions Stock Cutting tool
Guards o o Fixed Interlocked Adjustable Self-adjusting
Fixed guard on a bandsaw Wheel guard Blade guard Wheel guard
Fixed guard on a power press Stock entering danger zone Stock exit Transparent insert in front panel
Fixed guard enclosing belt and pulleys Inspection panel
Fixed guard on veneer clipping Guard
Fixed guard on a power squaring shear Blade guard Throat and gap guard
Ends and unused portion of press brake guarded o Power press brake (When used in a power press) o The requirements of 4123: 1 -5 -10 o Shall be applicable to power press brakes when End of the used for other than bending operations guarded Transparent guard Mounting bolt
Adjustable guard on horizontal bandsaw Adjustment knob Guard Blade
Adjustable guard on power press Adjustable bars
Pedestal grinder Rotating wheels Adjustable stock rest Point of operation Stock Operating control (on/off switch) Note: Grinding wheels are usually enclosed as shown. Base
Portable grinders
Adjustable guard on bandsaw
Adjustable guard on table saw Crank for height adjustment Handle for extending or retracting guard over blade Saw blade Guard
Adjustable guard on wood shaper Nut for height adjustment Guard Base of shaper blade
Adjustable guard on router Adjustment nuts Guard Stock Base of router blade
Self-adjusting guard on radial arm saw Handle Guard Anti-kickback device Blade
Self-adjusting guard on circular saw Guard retracted Stock Blade Guard
Self-adjusting guard table saw First guard Second guard
Self-adjusting guard on jointer Guard in rest position Guard Stock
Awareness barrier on back side of shear Awareness barrier
Awareness barrier on stitching machine Awareness barrier
Shields on a drill press and lathe Transparent shield Lathe Drill
Devices o Presence sensing • Photo-electrical • Radio-frequency • Electromechanical o Pullback o Restraint
Photoelectric presence sensing devices Danger area Sensing device
Photoelectric presence sensing devices cont:
Photoelectric presence sensing device on press brake
Radio-frequency presence sensing device on press Antenna Capacitance field
Electromechanical sensing device on an eye-letter o Similar safety devices are utilized on: spot welders and riveters Rocker-arm welder Air-operated welder Probe in contact with fingers, machine will not cycle
Pullback device on A power press Danger area Pullback mechanism Wristband
Pullback device on A press brake Nylon pullback straps are attached to wristbands
Restraint device on A power press
Devices o Safety controls • Safety trip control o Pressure-sensitive body bar o Safety triprod o Safety tripwire cable o Two-hand control o Two-hand trip
Pressure-sensitive body bar on rubber mill Bar
Safety triprod on a rubber mill
Safety tripwire cable on A calender Cable
Two-hand control buttons on a part-revolution clutch power press Control buttons
Two-hand trip buttons on a full-revolution clutch power press
Devices o Gates • Interlocked • Other o Location/distance
Horizontal injection molding machine with gate guards Gate Handle
Power press with gate guards Gate
Robot with fixed barrier guards Press Robot Stock conveyor Fixed barrier
Robot danger areas Danger area
Potential feeding and ejection methods to improve safety for the operator o o Automatic feed Semi-automatic feed Automatic ejection Semi-automatic ejection
Power press with automatic feed Transparent enclosure guard Stock feed roll Danger area Completed work Scrap material
Power press with chute feed Chute inclined as necessary for gravity feeding
Power press with sliding die Die stop Die slide Handle
Power press with sliding bolster Bolster in retracted position Die in stock placement or removal position (bolster in extended position)
Saw with auto indexing mechanism and traveling head Blade enclosure guards Stock Indexing mechanism
Holding tools Pliers with curved handles for two-handed usage Duckbill pliers Feeding tongs Vacuum-tongs for feeding positioning heavy formed parts Tong device used to tube or cup Right angle jaw tongs for handling flanged or cup shaped work pieces A lightweight tweeter made of steel springs Magnetic lifter “twist-off” Double magnet with release lever Double cup lifter with release button
Pushing devices Stock Push stick Push block
Five concerns on any machine o o o Safeguarding - guard, device, method Controls - control reliability Disconnect - lockable in off position Starter - magnetic (for drop-out protection) Covers - rotating components covered to 7 ft. from floor or from working platform.
Safety blocks installed on power presses Safety block
Lockout devices required for all machines
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