Subpart OMachine Guarding
Subpart O
o 1910.211 Definitionso 1910.212 General Requirements for all Machineso 1910.213 Woodworking Machineryo 1910.215 Abrasive Wheel Machineryo 1910.216 Mills and Calendarso 1910.217 Mechanical Power Presseso 1910.218 Forging Machineryo 1910.219 Mechanical Power-Transmission
Basics of machine safeguardingA good rule to remember is: o Any machine part; function; or process which
may cause injury must be safeguarded.
Basic areas of safeguardingo The point of operationo Power transmission apparatuso Other moving parts (reciprocating, transverse,
or rotating)
Motions
o Rotating (including in-running nip points)o Reciprocatingo Transverse
Nip point
Nip point
Nip point
Nip pointNip point
Nip points
In running nip points on rolls
Typical nip points
Nip point
Nip point
Nip point
A
B C
Nip points
Rotating hazards
Burr Rotating shaft and pulleys with projecting key and set screw
Rotating pulley with spokes and projecting burr on face of pulley
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
Guardso Prevent access to the danger areas
Deviceso Control access to the point of operation
Actions
o Cuttingo Punchingo Shearingo Bending
Different actions
Stock
Cutting tool
Guards
o Fixedo Interlockedo Adjustableo Self-adjusting
Fixed guard on a bandsaw
Wheel guard
Wheel guard
Blade guard
Fixed guard on a power press
Stock entering danger zone
Transparent insert in front panel
Stock exit
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
Transparent guard
Mounting bolt
End of the guarded
o Power press brake (When used in a power press)o The requirements of 4123:1-5-10o Shall be applicable to power press brakes when
used for other than bending operations
Adjustable guard on horizontal bandsaw
Blade
Guard
Adjustment knob
Adjustable guard on power press
Adjustable bars
Base
Operating control (on/off switch)
Stock
Point of operation
Adjustable stock rest
Rotating wheels
Note: Grinding wheels are usually enclosed as shown.
Pedestal grinder
Portable grinders
Adjustable guard on bandsaw
Adjustable guard on table saw
Crank for height adjustment
Guard
Saw blade
Handle for extending or retracting guard over blade
Adjustable guard on wood shaper
Guard
Base of shaper blade
Nut for height adjustment
Adjustable guard on router
GuardStock
Adjustment nuts
Base of router blade
Guard
Blade
Handle
Anti-kickback device
Self-adjusting guard on radial arm saw
Self-adjusting guard on circular saw
Stock
Blade
Guard
Guard retracted
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
LatheDrill
Devices
o Presence sensing• Photo-electrical
• Radio-frequency
• Electromechanical
o Pullbacko Restraint
Photoelectric presence sensing devices
Sensing device
Danger areaSensing device
Photoelectric presence sensing devices cont:
Photoelectric presence sensing device on press brake
Radio-frequency presence sensing device on press
Capacitance field
Antenna
Electromechanical sensing device on an eye-letter
o Similar safety devices are utilized on: spot welders and riveters
Probe in contact with fingers, machine will not cycleAir-operated
welderRocker-arm welder
Pullback device on A power press
Pullback mechanism
Wristband
Danger area
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 baro Safety triprodo 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 afull-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
Fixed barrier
Stock conveyor
Robot danger areas
Danger area
Potential feeding and ejection methods to improve safety for the operator
o Automatic feedo Semi-automatic feedo Automatic ejectiono Semi-automatic ejection
Power press with automatic feed
Scrap materialCompleted work
Transparent enclosure guard
Stock feed roll
Danger area
Power press with chute feed
Chute inclined as necessary for gravity feeding
Power press with sliding die
HandleDie stop
Die slide
Power press with sliding bolster
Bolster in retracted position
Die in stock placement or removal position(bolster in extended position)
Stock
Saw with auto indexing mechanism and traveling head
Blade enclosure guards
Indexing mechanism
Duckbill pliers
Feeding tongs
Vacuum-tongs for feeding positioning heavy formed parts
Tong device used to tube or cup
Pliers with curved handles for two-handed usageRight angle jaw tongs for handling flanged or cup shaped work pieces
A lightweight tweetermade of steel springs
Magnetic lifter “twist-off”
Double magnet withrelease lever
Double cup lifterwith release button
Holding tools
Push block
Stock
Pushing devices
Five concerns on any machineo Safeguarding - guard, device, methodo Controls - control reliabilityo Disconnect - lockable in off positiono Starter - magnetic (for drop-out protection)o Covers - rotating components covered to 7ft.
from floor or from working platform.
Safety blocks installed on power presses
Safety block
Lockout devices required for all machines