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