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Why are machines not guarded?

• No one would stick their arm, hand, finger, head, etc. in there.

• No one is supposed to be back there, in there, around it while it is running.

• The machine came that way; it never had a guard.

• I’ve been doing it this way for twenty years without any problems.

Why are machines not guarded?

(cont.)

• The guard is in the way

• The OSHA inspector didn’t say anything

about it.

• We’ll put it back on if OSHA comes.

Any Hazards?

Methods of machine

safeguarding

• Physical guards

• Devices

• Location/Distance

Guards

• Fixed

• Interlocked

• Adjustable

• Self-adjusting

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Fixed Guard

Provides a barrier - a permanent part of the

machine, preferable to all other types of

guards.

Interlocked Guard

When this type of guard is opened or removed,

the tripping mechanism and/or power

automatically shuts off or disengages, and the

machine cannot cycle or be started until the

guard is back in place.Interlocked

guard on

revolving

drum

Adjustable Guard

Provides a barrier which may be

adjusted to facilitate a variety of

production operations.

Bandsaw blade

adjustable

guard

Self-Adjusting Guard

Provides a barrier which moves according

to the size of the stock entering the danger

area.

Circular table saw

self-adjusting

guard

Safeguarding devices

• Presence sensing

• Pullback

• Restraint

• Safety controls and trips

• Gates

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Safeguarding devices

• Presence sensing

• Pullback

• Restraint

• Safety controls and trips

• Gates

Pullback Device

• Utilizes a series of cables

attached to the operator’s

hands, wrists, and/or arms

• Primarily used on machines

with stroking action

• Allows access to the point of

operation when the slide/ram is

up

• Withdraws hands when the

slide/ram begins to descend

Pullback Device (cont’d)

• Hands in die, feeding

• Point of operation exposed

• Pullback device attached

and properly adjusted

• Die closed

• Hands withdrawn from

point of operation by

pullback device

Restraint Device

• Uses cables or straps

attached to the operator’s

hands and a fixed point

• Must be adjusted to let the

operator’s hands travel

within a predetermined safe

area

• Hand-feeding tools are often

necessary if the operation

involves placing material

into the danger area

Safety Tripwire Cables

• Device located around the

perimeter of or near the

danger area

• Operator must be able to

reach the cable to stop the

machine

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Two-Hand Control

.

• Requires constant, concurrent

pressure to activate the

machine

• The operator’s hands are

required to be at a safe

location (on control buttons)

and at a safe distance from the

danger area while the machine

completes its closing cycle

Gate

• Movable barrier device which protects the operator at the

point of operation before the machine cycle can be started

• If the gate does not fully close, machine will not function

Gate

Open

Gate Closed

Safeguarding by

Location/Distance

• Locate the machine or its

dangerous moving parts so

that they are not accessible

or do not present a hazard

to a worker during normal

operation

• Maintain a safe distance

from the danger area

Automatic Feed(shown on power press)

Transparent EnclosureGuard

Stock FeedRoll

DangerArea

Completed Work

Robots

• Machines that load and

unload stock, assemble

parts, transfer objects, or

perform other tasks

• Best used in high-

production processes

requiring repeated

routines where they

prevent other hazards to

employees

Protective Shields

These do not give complete protection from

machine hazards, but do provide some

protection from flying particles, splashing

cutting oils, or coolants.

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1910.212(a)(1) Types of guarding• One or more methods of machine guarding

shall be provided to protect the operator and

other employees in the machine area from

hazards such as those created by:

– Point of operation,

– Ingoing nip points,

– Rotating parts,

– Flying chips and sparks

1910.212(a)(2) General

requirements for machine guards • Guards shall be affixed to the machine where

possible and secured elsewhere if for any

reason attachment to the machine is not

possible

• The guard shall be such that it does not offer an

accident hazard in itself

1910.212(a)(3) Point of Operation

• Point of operation is the

area on a machine where

work is actually

performed upon the

material being processed

• The point of operation

of machines whose

operation exposes an

employee to injury,

shall be guarded

1910.212(a)(3)(iii) Hand Tools

• Special hand tools for

placing and removing

material shall be such as

to permit easy handling

of material without the

operator placing a hand

in the danger zone*

*Such tools shall not be in

lieu of other guarding

required by this section, but

can only be used to

supplement protection

provided.

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1910.212(a)(3)(iv)

Examples of machines • Types of machines which normally require point

of operation guarding:

– Mills

– Drills

– Grinders

– Power presses

– Shears

– Saws

1910.212(a)(4) Barrels,

containers, and drums

• Revolving drums, barrels,

and containers shall be

guarded by an enclosure

which is interlocked with

the drive mechanism, so

that the barrel, drum, or

container cannot revolve

unless the guard

enclosure is in place

1910.212(a)(5) Exposure of blades• When the periphery of the blades of a fan is

less than seven (7) feet above the floor or

working level, the blades shall be guarded

• The guard shall have openings no larger than

one-half (1/2) inch.

1910.212(b) Anchoring fixed

machinery

• Machines designed for a fixed location shall be

securely anchored to prevent walking or moving

This pedestal grinder is

designed for anchoring,

and is not anchored,

creating a potential

hazard

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Definitions

• "Flanges" means collars, discs or plates

between which wheels are mounted and are

referred to as adapter, sleeve, or back up type.

See paragraph (c) of 1910.215 for full

description.

• "Off-hand grinding" means the grinding of any

material or part which is held in the operator's

hand.

1910.215(a)(2) Guard design

• The safety guard

shall cover the

spindle end, nut,

and flange

projections

• The safety guard

shall be mounted

so as to maintain

proper alignment

with the wheel

1910.215(a)(2) Guard design

• The strength of the fastenings shall exceed the

strength of the guard, except:

– Where the work provides suitable protection, the

guard may expose the spindle end, nut and flange

– Where the work entirely covers the side of the

wheel the side cover(s) of the guard may be omitted

1910.215(a)(4) Work Rests• On off hand grinding, work rests are required, to

support the work

• Rigid construction,and adjustable with wheel

wear

• Must be kept closely adjusted, max gap = 1/8"

to prevent work from jamming & breaking wheel

• Securely clamped after each adjustment

• Adjustments made only when wheel is stopped

Work rest is closely

adjusted

Maximum wheel exposure = 90º

Maximum angle of exposure

above the horizontal = 65º

Angular exposure for wheel periphery

Horizontal plane of the spindle

For bench and floor stand grinders

1910.215(b)(9) Exposure

adjustment• Safety guards of the type where the

operator stands in front of the

opening, shall be so constructed so

that the peripheral protecting

member can be adjusted to the

constantly decreasing size of the

wheel

• The distance between the periphery

and the adjustable tongue guard

shall never exceed one-fourth inch

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1910.215 (d) Mounting• Inspection:

– Immediately before mounting, all wheels shall be

closely inspected and sounded by the user (ring

test) to make sure they have not been damaged in

transit, storage, or otherwise

– The spindle speed of the machine shall be checked

before mounting of the wheel to be certain that it

does not exceed the maximum operating speed

marked on the wheel

• Sound the wheel by

tapping around the

wheel periphery with

a wood handled

screwdriver*

• Good wheel portions

will “ring” like a bell

• Cracks will sound

“dead”

1910.215 (d) Mounting -Ring Test

*A non-metallic implement,

wood mallets may be

needed for larger wheels

• The spindle speed of

the machine shall be

checked before

mounting of the

wheel to be certain

that it does not

exceed the

maximum operating

speed marked on the

wheel.

1910.215 (d) Mounting

Compare this number to the

spindle speed on the grinder

motor

1910.219(b)(1) Flywheels

• Flywheels 7 feet or less

above the ground shall be

guarded

• Sheet, perforated, or

expanded metal or woven

wire, or with

• Guard rails between 15 to 20

inches from flywheel rim

• Toe board if within 12 inches

of floor or extends into a pit

• All projections shall be

covered

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1910.219.(c) Shafting

• Each continuous line of shafting shall be

secured in position against excessive end

movement

• Inclined and vertical shafts* shall be securely

held in position against endwise thrust

*Particularly inclined idler shafts

• All exposed parts of horizontal shafting 7 ft. or

less above the floor shall be guarded (except:

runways used for oiling or running adjustments)

by a stationary casing, or by a trough

• Troughs must enclose sides and top, or sides

and bottom of shafting as location requires

1910.219.(c) Shafting

Projecting end shafts shall

present a smooth edge

and project not more than

1/2 the diameter of the

shaft

Unused key ways shall be

filled up or covered

1910.219.(c) Shafting 1910.219(d) Pulleys• Pulleys, any parts of which are seven feet or

less from the floor or working platform, shall be

guarded in accordance with the standards

specified in paragraphs (m) & (o)

• Pulleys serving as balance wheels (e.g., punch

presses) on which the point of contact between

belt and pulley is more than six feet six inches

from the floor or platform may be guarded with

a disc covering the spokes

Distance between

pulleys = 2 inches

Belt width = three inches

Guides must be placed

in this area

Example

seven ft. minimumFloor

Unguarded portion

Guard

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1910.219 (f) Gears sprockets

and chains• Gears, sprockets and

chains shall be guarded by

one of the following

methods:

• By a complete enclosure; or

• By a standard guard as in

paragraph (o), at least

seven feet high, extending

six inches above the mesh

point of the gears; or

1910.219 (o) Approved Materials

• (1)(i)(a)All guards shall be rigidly braced every

three (3) feet or fractional part of their height to

some fixed part of machinery or building

structure.

• Where guard is exposed to contact with moving

equipment additional strength may be

necessary.

1910.219(o)(2) Wood guards

• Wood guards may be used in the woodworking

and chemical industries, in industries where the

presence of fumes or where manufacturing

conditions would cause the rapid deterioration

of metal guards

• In construction work and outdoors where

extreme cold or heat make metal guards and

railings undesirable

height 42"

Posts not more than 8' apart,

permanent, substantial, smooth, w/

no protruding nails, bolts or splintersToeboards at least 4" high

midrail half way in-betweenIf wood, 2"x 4" toprail

1910.219(o)(2) Wood guards