slide 1 (of 185) objectives objectives course no. 204 machinery and machine guarding standards...

Slide 1 (of 185)

ObjectivesObjectives Course No. 204 Machinery and Machine Guarding

Standards Course

• Identify basic machinery terms• Identify common machines found within a

broad spectrum of industries• Identify hazards that occur in or on

machinery• Select the appropriate OSHA STANDARD

that applies to a hazard• Present options to achieve abatement

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• The point of operation: that point where work is performed on the material, such as cutting, shaping, boring, or forming of stock.

• Power transmission apparatus: all components of the mechanical system which transmit energy to the part of the machine performing the work. These components include flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears.

• Other moving parts: all parts of the machine which move while the machine is working. These can include reciprocating, rotating, and transverse moving parts, as well as feed mechanisms and auxiliary parts of the machine.

Dangerous moving parts in these three basic areas need safeguarding:

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Rotating pulley

Rotating shaft

Rotating coupling

Burr

Hazardous Rotating Motion

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Rotating (including in-running nip points)

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Hazardous Reciprocating Motion

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Hazardous Transverse Motion

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What must a safeguard do to protect workers against

mechanical hazards?

Slide 8 (of 185)

• Prevent contactPrevent contact::

– The safeguard must prevent hands, arms, or any part of a worker's body or clothing from making contact with dangerous moving parts. A good safeguarding system eliminates the possibility of the operator or other workers placing parts of their bodies near hazardous moving parts.

• SecureSecure::

– Workers should not be able to easily remove or tamper with the safeguard, because a safeguard that can easily be made ineffective is no safeguard at all. Guards and safety devices should be made of durable material that will withstand the conditions of normal use. They must be firmly secured to the machine.

• Protect from falling objectsProtect from falling objects:: – The safeguard should ensure that no objects can fall into moving parts.

A small tool which is dropped into a cycling machine could easily become a projectile that could strike and injure someone.

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• Create no new hazardsCreate no new hazards::

– A safeguard defeats its own purpose if it creates a hazard of its own such as a shear point, a jagged edge, or an unfinished surface which can cause a laceration. The edges of guards, for instance, should be rolled or bolted in such a way that they eliminate sharp edges.

• Create no interferenceCreate no interference::

– Any safeguard which impedes a worker from performing the job quickly and comfortably might soon be overridden or disregarded. Proper safeguarding can actually enhance efficiency since it can relieve the worker's apprehensions about injury.

• Allow safe lubricationAllow safe lubrication::

– If possible, one should be able to lubricate the machine without removing the safeguards. Locating oil reservoirs outside the guard, with a line leading to the lubrication point, will reduce the need for the operator or maintenance worker to enter the hazardous area.

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Machine SafeguardingClassifications

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• Guards•Fixed• Interlocked•Adjustable•Self-adjusting

• Devices– Presence Sensing

•Photoelectric (optical)

•Radiofrequency (capacitance)

•Electromechanical– Pullback– Restraint

– Safety Controls•Safety trip control

– Pressure-sensitive body bar

– Safety tripod– Safety tripwire

cable• Two-hand control• Two-hand trip

– Gates• Interlocked•Other

Machine Safeguarding Classifications

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• Location/Distance• Potential Feeding and

Ejection Methods – Automatic feed– Semi-automatic

feed– Automatic ejection– Semi-automatic

ejection– Robot

Machine Safeguarding Classifications

• Miscellaneous Aids– Awareness

barriers– Miscellaneous

protective shields– Hand-feeding tools

and holding fixtures

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Advantages– Can be constructed to suit many

specific applications– In-plant construction is often

possible– Can provide maximum protection – Usually requires minimum

maintenance– Can be suitable to high

production, repetitive operations

Limitations– May interfere with visibility– Can be limited to specific

operations– Machine adjustment and repair

often require its removal, thereby necessitating other means of protection for maintenance personnel

Fixed Guards - Provides a Barrier

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Fixed Point of Operation Guard

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Safeguarding Action – Shuts off or disengages power and

prevents starting of machine when guard is open; should require the machine to be stopped before the worker can reach into the danger area

Advantages– Can provide maximum protection – Allows access to machine for

removing jams without time-consuming removal of fixed guards

Limitations– Requires careful adjustment and

maintenance– May be easy to disengage

Interlocked

Slide 16 (of 185)

Safeguarding Action – Provides a barrier which may be

adjusted to facilitate a variety of production operations

Advantages– Can be constructed to suit many

specific applications – Can be adjusted to admit varying

sizes of stock

Limitations– Hand may enter danger area -

protection may not be complete at all times

– May require frequent maintenance and/or adjustment

– The guard may be made ineffective by the operator

– May interfere with visibility

Adjustable

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Safeguarding Action

– Provides a barrier which moves according to the size of the stock entering danger area

Advantages– Off-the-shelf guards are often

commercially available

Limitations– Does not always provide

maximum protection– May interfere with visibility– May require frequent maintenance

and adjustment

Self-Adjusting

Slide 18 (of 185)

Safety DevicesSafety Devices• Stop the machine if a hand or any part of the

body is inadvertently placed in the danger area;• Restrain or withdraw the operator's hands from

the danger area during operation;• Require the operator to use both hands on

machine controls, thus keeping both hands and body out of danger; or

• Provide a barrier which is synchronized with the operating cycle of the machine in order to prevent entry to the danger area during the hazardous part of the cycle.

Slide 19 (of 185)

Safeguarding Action – Machine will not start cycling when

the light field is interrupted – When the light field is broken by any

part of the operator's body during the cycling process, immediate machine braking is activated

Advantages– Can allow freer movement for

operator; simplicity of use; no adjustments required

Limitations– Does not protect against mechanical

failure– May require frequent alignment and

calibration– Excessive vibration may cause lamp

filament damage and premature burnout

– Limited to machines that can be stopped

Photoelectric

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Safeguarding Action– As the machine begins to cycle, the

operator's hands are pulled out of the danger area

Advantages– Eliminates the need for auxiliary

barriers or other interference at the danger area

Limitations– Limits movement of operator– May obstruct work-space around

operator– Adjustments must be made for

specific operations and for each individual

– Requires frequent inspections and regular maintenance

– Requires close supervision of the operator's use of the equipment

Pullbacks

Slide 21 (of 185)

Safeguarding Action– Prevents the operator from

reaching into the danger area

Advantages– Little risk of mechanical failure

Limitations– Limits movements of operator– May obstruct work-space– Adjustments must be made for

specific operations and each individual

– Requires close supervision of the operator's use of the equipment

Restraint (holdback)

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Safeguarding Action

– Stops machine tripped

Advantages– Simplicity of controls

Limitations– Other guards are also required for

operator protection--usually fixed barrier guards

– Requires frequent maintenance – May not be adaptable to stock

variation

Safety Trip Controls

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Safety Trip Controls (cont’d)

• When pressed by hand, the safety tripod deactivates the machine.

• Because it has to be actuated by the operator during an emergency situation, its proper position is also critical.

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Safety Tripwire Cables Are located around the perimeter of or near the danger area.The operator must be able to reach the cable with either handto stop the machine.

Calender equipped with this type of control.

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Safeguarding Action – Concurrent use of both hands is

required, preventing the operator form entering the danger area

Advantages– Operator’s hands are at a

predetermined location– Operator’s hands are free to pick

up a new part after first half of cycle is completed

Limitations– Requires a partial cycle machine

with a brake– Some two-hand controls can be

rendered unsafe by holding with arm or blocking, thereby permitting one-hand operation Protects only the operator

Two Hand Controls

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Not Two Hand Controls

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Two Hand Trip• Requires concurrent application of both of the operator's control buttons

to activate the machine cycle, after which the hands are free.

• Trips must be placed far enough from the point of operation to make it impossible for the operator to move his or her hands from the trip buttons or handles into the point of operation before the first half of the cycle is completed.

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Gate• Movable barrier which protects the operator at the point of

operation before the machine cycle can be started.

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Robots

Press

FixedBarrier

Robot

StockConveyor

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Miscellaneous

Awareness Barrier

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Shields

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Part 1910 Subpart O - Machinery and Machine Guarding

• 1910.211 - Definitions.

• 1910.212 - General requirements for all machines.

• 1910.213 - Woodworking machinery requirements.

• 1910.214 - Cooperage machinery. (Reserved)

• 1910.215 - Abrasive wheel machinery.

• 1910.216 - Mills and calenders in the rubber and plastics industries.

• 1910.217 - Mechanical power presses.

• 1910.218 - Forging machines.

• 1910.219 - Mechanical power-transmission apparatus.

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Section 1910.212 is a general (or (horizontal) standard that applies to all machines not specifically mentioned elsewhere in other sections of Subpart O. Other sections are specific (vertical) standards that apply to particular types of machines; e.g., Section 1910.213 applies to woodworking machinery.

Horizontal v. Vertical Horizontal v. Vertical

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Machine guarding. 1910.212(a)(1)Machine guarding. 1910.212(a)(1)• 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.

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1910.212(a)(2)• 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.

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1910.212(a)(3)(ii) The point of operation of machines whose operation exposes an employee to injury, shall be guarded.

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1910.212(a)(4)Revolving Drums, Barrels, and Containers

• Must be guarded by an enclosure which is interlocked with the drive mechanism.

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1910.212(a)(5) Fan Blades• When the periphery of the blades of a fan is less

than 7 feet above the floor or working level, the blades must be guarded with a guard having openings no larger than ½ inch.

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1910.212(a)(6)Anchoring Fixed Machinery– Machines designed for a fixed location must

be securely anchored to prevent walking or moving.

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What machines are covered by 910.212

?

Slide 41 (of 185)

Presenting1910.212

Slide 42 (of 185)

OSHA Standards:• 1910.212(a)(1)

Machine guarding• 1910.212(a)(3)(ii)

Point of operation Hazards:

• Contact with pinch points

• Struck by hot metals• Caught in two die

halves Reference Standard: Guarding Method:

• Barrier guard

GatesVideo Clip

Not in Handout

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Unguarded Dough Mixer

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Ingredient Mixer

OSHA Standards:• 1910.212(a)(1)

Rotating Parts• 1910.212(a)(3)(ii)

Point of operation Hazards:

• Contact with rotating parts

Reference Standard:• ANSI/AHAM FM-1

(food mixers) Guarding Method:

• Interlocks What happened?

• Employee by-passed interlock

Result - Death

Slide 45 (of 185)

Injection Molding Machine

OSHA Standards:• 1910.212(a)(1) Rotating Parts

• 1910.212(a)(3)(ii) Point of operation

Reference Standard:• ANSIB151.1

Guarding Method:• Interlocked barrier gate

GuardedNot Guarded

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Injection Molding Machine(Plastic Molding)

1 - Electrical Interlock2 - Hydraulic Interlock

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Die Halves Stationary Platen

175 Ton Injection Molding Machine

Interlocked Safety Gate

Mechanical Blocking Mechanism

Slide 48 (of 185)

Injection Molding Machine

3 - Mechanical Blocking MechanismPrevents the dies from closing

Slide 49 (of 185)

OSHA Standards:• 1910.212(a)(1)

Machine guarding• 1910.212(a)(3)(ii)

Point of operation Hazards:

• Contact with pinch points

• Struck by hot metals• Caught in two die

halves Reference Standard:

• Society of Die Cast Engineers – Die Cast Machine Safety)

Guarding Method:• Barrier guard

Die Casting MachinesVideo Clip

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Die Casting Operation OSHA Standards:

• 1910.212(a)(1) Nipping points

• 1910.212(a)(3)(ii) Point of operation

Hazard (s):• Stuck-by molten

aluminum• Contact with moving

machine parts Reference Standard:

• Society of Die Cast Engineers – Die Cast Machine Safety

Guarding Method:• Barrier Guard Die Spit Shield

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Tubing Bender OSHA Standards:• 1910.212(a)(1) Pinch

Point – Struck by

• 1910.212(a)(3)(ii) Point of operation

Hazard (s):• Caught in the clamp die

• Contact with moving machine parts

Reference Standard:• ANSI B11.15 Pipe Tube

and Shape Bending

Guarding Method:• Barrier guard

• Foot pedal operation

• Presence sensing device

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Swing Arm in Motion

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Addison Tube Bender

Safety Matand

Foot Pedal Control

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Mechanical Power Press Brake

OSHA Standards:• 1910.212(a)(3)(ii) Point of

operation Hazards:

• Caught in the point of operation

Reference Standard:• ANSIB11.3 Power Press Brakes

Guarding Method:• Presence Sensing Devices• Two hand controls• Automatic barrier gates• Restraint device

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Point of operation hazard – CPL 2-1.25Guidelines for point of operation guarding forpower press brakes

4 4 inchesinches 4 “

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Press Brake Foot Treadle OperatedWith a Restraint Device

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Photo electric sensingacross face and barrieracross the ends of the press brake

Press brake

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The Back of The Press Brake

Awareness Guard

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Horizontal Metal Cutting Band Saw

OSHA Standards:• 1910.212(a)(1) Machine

Guarding Hazards:

• Contact with the unused portion of the saw blade

Reference Standard:• ANSIB11.10 Sawing

Guarding Method:• Telescoping barrier guard

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Metal Cutting Radial Saw

OSHA Standards:• 1910.212(a)(3)(ii) Point of

operation guarding Hazards:

• Contact with the saw blade

Reference Standard:• ANSIB11.10 Sawing

Guarding Method:• Side barrier guard

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OSHA Standards:• 1910.212(a)(1)

Nipping point Hazards:

• Contact with rotating parts

Reference Standard:• ANSI B20.1

Conveyors Guarding Method:

• Barrier guard• Isolation• Control relocation

Meat auger

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Guard does not meet requirement of Table O-10

Screw Conveyor

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OSHA Standards:• 1910.212(a)(3)(ii) Point of

operation guarding Hazards:

• Contact between the forming rolls and the material

Reference Standard:• ANSIB11.12 Roll forming and Roll

Bending Guarding Method:

• Barrier guard (interlocked)• Presence sensing device

Forming Mill Table

May use safety trip wire???

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Forming Mill

In-running Nip Point

Point of Operation

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Forming Mill

Shows the process of metal forming – Metal is being pulled through dies and formed as it progresses.

Slide 66 (of 185)

OSHA Standards:• 1910.212(a)(1) Machine

guarding Hazards:

• Contact between the belt and the pulley nip (drum)

Reference Standard:• ANSIB 20.1 Conveyors

Guarding Method:• Barrier guard • Isolation

Back of a Shear – Material Take-off Conveyor

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Nip Point

Conveyor Nip

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Scissor Lift Table

OSHA Standards:• 1910.212(a)(1) Machine

guarding Hazards:

• Contact between the scissors arms

Reference Standard:• ??

Guarding Method:• Telescoping barrier guard • Isolation

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Pyramid or Pinch Roll Forming

OSHA Standards:• 1910.212(a)(3)(ii) Point of

operation guarding Hazards:

• Contact in the point of operation

Reference Standard:• ANSI B11.12 Roll forming and

bending Guarding Method:

• Isolation• Limited barrier guards

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Pyramid or Pinch Roll Forming

Point of OperationPoint of Operation

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Roll Former Isolation Guarding

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REELPaper Mill Pope

OSHA Standards:• 1910.212(a)(3)(ii) Point of

operation guarding Hazards:

• Contact in the point of operation

Reference Standard:• ANSI B11.12 Roll forming and

bending Guarding Method:

• Isolation• Limited barrier guards

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REEL – Threading the MachinePaper Mill Pope

In Running Nip Point

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REEL – Threading the MachinePaper Mill Pope

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REELPaper Mill Pope

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REELPaper Mill Pope

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Primary Arm Guard

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Lathe

OSHA Standards:• 1910.212(a)(1)

Rotating parts Hazards:

• Contact with rotating parts

Reference Standard:• ANSI B11.6 Lathes

Guarding Method:• Barrier guard

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Lathe

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Lathe Chip Shield

Slide 81 (of 185)

Tapper

OSHA Standards:• 1910.212(a)(1) Machine guarding• 1910.212(a)(3)(ii) Point of operation

guarding Hazards:

• Contact with rotating parts, chips and coolant

• Contact in the point of operation

Reference Standard:• ANSI B11.8 Tapper

Guarding Method:• Barrier guards and/or isolation

Slide 82 (of 185)

Vertical Boring Mills

OSHA Standards:• 1910.212(a)(1) Machine

guarding Hazards:

• Contact with rotating parts

Reference Standard:• ANSI B11. 8 Milling, drilling and

boring machines Guarding Method:

• Barrier guards

Slide 83 (of 185)

Vertical Boring Mills

Slide 84 (of 185)

Vertical Boring MillChip, and Rotating Part Guard

Slide 85 (of 185)

Horizontal Boring Mill

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Mechanical Shear

OSHA Standards:• 1910.212(a)(1) Machine guarding• 1910.212(a)(3)(ii) Point of operation

guarding Hazards:

• Contact with shear blade• Contact with hold down

Reference Standard:• ANSI B11. 4 Shears

Guarding Method:• Barrier guard

Hold down

Slide 87 (of 185)

Shear in Operation

Helper is exposed

Slide 88 (of 185)

Modified Guard

Hydraulic Shear

Blade

Slide 89 (of 185)

OSHA Standards:• 1910.212(a)(1)

Machine guarding• 1910.212(a)(3)(ii)

Point of operation Hazards:

• Contact with mold halves

• Contact with shuttle Guarding Method:

• Barrier guards• Presence devices

Core Making MachinesVideo Clip

Slide 90 (of 185)

Iron Worker OSHA Standards:• 1910.212(a)(1)

Machine guarding• 1910.212(a)(3)(ii)

Point of operation Hazards:

• Contact with angle shear or notcher

• Contact with the punch and die

Guarding Method:• Barrier guards

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Woodworking Machinery Requirements

1910.213

Slide 92 (of 185)

• 10.213(a)(9) All belts, pulleys, gears, shafts, and moving parts must be guarded in accordance with the specific requirements of 1910.219.

Belts

Slide 93 (of 185)

• Circular table saws must have Circular table saws must have a hooda hood over the portion of the saw above the table, so mounted that the hood will automatically adjust itself to the thickness of and remain in contact with the material being cut.

• Must have a spreaderMust have a spreader aligned with the blade, spaced no more than one-half inch behind the largest blade mounted in the saw.

• If used for rippingIf used for ripping must have nonkickback fingers or dogs.

1910.213(c) Rip Saws

Slide 94 (of 185)

1910.213(d) Hand fed Crosscut SawShall Meet Requirements of (c)(1)

Slide 95 (of 185)

• Hood that will completely enclose the upper half of the saw, the arbor end, and the point of operation at all positions of the saw.

• Constructed in such a manner and of such material that it will protect the operator from flying splinters and broken saw teeth.

• Automatically cover the lower portion of the blade, so that when the saw is returned to the back of the table the hood will rise on top of the fence, and when the saw is moved forward the hood will drop on top of and remain in contact with the table or material being cut.

10.213(g) Swing Cutoff Saws

Slide 96 (of 185)

Slide 97 (of 185)

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1910.213 (h) Radial Saws• Upper hoodUpper hood that completely enclose the

upper portion of the blade down to a point that will include the end of the saw arbor.

• Sides of the lower exposed Sides of the lower exposed portionportion of the blade guarded to the full diameter of the blade.

• Radial saw used for rippingRadial saw used for ripping shall be provided with nonkickback fingers or dogs .

• Adjustable stopAdjustable stop to prevent the forward travel of the blade beyond the position necessary to complete the cut in repetitive operations.

• Installation such that the front Installation such that the front endend of the unit will be slightly higher than the rear, so as to cause the cutting head to return gently to the starting position when released by the operator.

Slide 99 (of 185)

Radial Arm Saws

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Slide 101 (of 185)

1910.213 (i) Bandsaws andBand Resaws• All portions of the saw blade shall be

enclosed or guarded, except for the working portion of the blade between the bottom of the guide rolls and the table.

• Wheels fully encased.

• Outside periphery of the enclosure shall be solid.

• Front and back enclosed by solid material or by wire mesh or perforated metal.

• Guard for the portion of the blade between the sliding guide and the upper-saw-wheel guard shall protect the saw blade at the front and outer side.

• Self-adjusting to raise and lower with the guide.

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Band Saw

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Band Saw

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10.213(j)(3) Hand-Fed Jointer • Automatic guard which will cover all the section of the head on the

working side of the fence or gage.

• Effectively keep the operator's hand from coming in contact with the revolving knives.

• Automatically adjust itself to cover the unused portion of the head and shall remain in contact with the material at all times.

Slide 106 (of 185)

• Cutting heads of each wood shaper, hand-fed panel raiser, or other similar machine not automatically fed, shall be enclosed with a cage or adjustable guard so designed as to keep the operator's hands away from the cutting edge.

1910.213(m)(1) Wood Shapers and Similar Equipment

Slide 107 (of 185)

10.213(o)(2) Cutting Heads on Wood- Turning Lathes• Covered as completely as possible by hoods or shields.

Slide 108 (of 185)

• Feed rolls of self-feed sanding machines must be protected with a semi cylindrical guard to prevent the hands of the operator from coming in contact with the in-running rolls at any point.

• Guard must be constructed of heavy material, preferably metal, and firmly secured to the frame carrying the rolls so as to remain in adjustment for any thickness of stock.

• The bottom of the guard should come down to within three-eighths inch of a plane formed by the bottom or contact face of the feed roll where it touches the stock.

1910.213(p)(1) Sanding Machines

Slide 109 (of 185)

Circular Sander

Slide 110 (of 185)

Unguarded belt sander

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Slide 112 (of 185)

Saw Blade

1910.213(s)(7)&(8)

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Table Saw

Slide 114 (of 185)

Swing Cut off Saw

Slide 115 (of 185)

Table Saw

Slide 116 (of 185)

Table Saw

Slide 117 (of 185)

Belt Sander

Slide 118 (of 185)

Table Saw

Slide 119 (of 185)

Table Saw

Slide 120 (of 185)

Power Molding Machine

Slide 121 (of 185)

Table Saw

Slide 122 (of 185)

Table Saw

Slide 123 (of 185)

Dado Blade on Radial Saw

Slide 124 (of 185)

Power Fed Rip Saw

Slide 125 (of 185)

Radial Arm Saw

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Radial Arm Saw

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1910.215 AbrasiveWheel Machinery

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Slide 131 (of 185)

• The safety guard shall cover the spindle end, nut, and flange projections.

1910.215(a)(2) Guard Design

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Safety Guard

Slide 133 (of 185)

• On offhand grinding machines, work rests shall be used to support the work. They shall be of rigid construction and designed to be adjustable to compensate for wheel wear. Work rests shall be kept adjusted closely to the wheel with a maximum opening of one-eighth inch to prevent the work from being jammed between the wheel and the rest, which may cause wheel breakage. The work rest shall be securely clamped after each adjustment. The adjustment shall not be made with the wheel in motion.

1910.215(a)(4) Work Rests

Work rest 1/8”

Slide 134 (of 185)

Exposure adjustment

one-fourth inch

1910.215(b)(9) Tongue Guard

Slide 135 (of 185)

• (1) Inspection. – 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 - Wheel Speed

Slide 136 (of 185)

• (1) Inspection– Wheels should be tapped

gently with a light nonmetallic implement, such as the handle of a screwdriver for light wheels, or a wooden mallet for heavier wheels. If they sound cracked (dead), they shall not be used. This is known as the "Ring Test".

1910.215(d) Mounting - Ring Test

“Ring test”

Slide 137 (of 185)

• Self Closing Guard– Effective two years after approval of this

revision for existing machines, all floor stand grinders for use with a 24” diameter wheels or larger where personnel are required to be in the plane of rotation of the wheel shall be equipped with guards which close automatically in case of wheel breakage. Other guard designs which provide equivalent protection to the personnel in the plane of rotation of the wheel may be used.

FLOOR STAND GRINDERSANSI B.7.1-1988 E 4.3.2

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Slide 139 (of 185)

Guard Down

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Surface grinder with top guard

Slide 142 (of 185)

29CFR 1910.219 Mechanical Power-Transmission

Apparatus

Slide 143 (of 185)

• (1) This section covers all types and shapes of power-transmission belts, except the following when operating at two hundred and fifty (250) feet per minute or less:– (i) Flat belts one (1) inch or less in

width,– (ii) Flat belts two (2) inches or less

in width which are free from metal lacings or fasteners,

– (iii) Round belts one-half (1/2) inch or less in diameter; and

– (iv) Single strand V-belts, the width of which is thirteen thirty-seconds (13/32) inch or less.

1910.219(a) General Requirements

Slide 144 (of 185)

• (2) Vertical and inclined belts (paragraphs (e) (3) and (4) of this section) if not more than two and one-half (2 1/2) inches wide and running at a speed of less than one thousand (1,000) feet per minute, and if free from metal lacings or fastenings may be guarded with a nip-point belt and pulley guard.

1910.219(a) General Requirements

Slide 145 (of 185)

Belt speed exceeds one thousand (1,000) feet per minute

Slide 146 (of 185)

• (1) Flywheels located so that any part is seven (7) feet or less above floor or platform shall be guarded in accordance with the requirements of this subparagraph:

1910.219(b) Flywheels

(7) feet or less above floor or platform shall be guarded

Slide 147 (of 185)

This is in further response to your letter dated April 5, 1983, concerning the guarding of flywheels on power presses.

The Occupational Safety and Health Administration's General Industry Standards 29 CFR 1910.219(b)(1) and (b)(1)(vi) require guarding of the press flywheel. Furthermore, the latter provision requires that flywheels above working areas be provided with guards of sufficient strength to contain the flywheel in the event of shaft or wheel mounting failure.

Reference to ANSI 815.1-1972, the current version of the source standard, rapidly demonstrates that structural failures are possible. Appendix AB.1 of ANSI 815.1 indicates that failures of a fatigue nature can be anticipated, particularly for older machines that have been continually exposed to cyclic leads.

Therefore, substantial guarding is necessary to provide safety. That company die setter's need to have easy access to the flywheel for die-setting for is completely valid and should be a major consideration of the guarding provided. In that regard, the guard configuration enclosed is recommended for consideration.

LETTER OF INTERPRETATION

Slide 148 (of 185)

1910.219(c) Shafting

Rotating pulley

Rotating shaft

Rotating coupling

Burr

Slide 149 (of 185)

• (i) All exposed parts of horizontal shafting seven (7) feet or less from floor or working platform, excepting runways used exclusively for oiling, or running adjustments, shall be protected by a stationary casing enclosing shafting completely or by a trough enclosing sides and top or sides and bottom of shafting as location requires.

1910.219(c)(2) Guarding Horizontal Shafting

Shafting must be guarded

Slide 150 (of 185)

• (i) Projecting shaft ends shall present a smooth edge and end and shall not project more than one-half the diameter of the shaft unless guarded by nonrotating caps or safety sleeves.

• (ii) Unused keyways shall be filled up or covered.

1910.219(c)(4) Projecting Shaft Ends

Shafting shall not extend morethan 1/2 the diameter of theshaft unless guarded

Slide 151 (of 185)

• (1) Pulleys, any parts of which are seven (7) feet or less from the floor or working platform, shall be guarded in accordance with the standards specified in paragraphs (m) and (o) of this section.

1910.219(d) Pulley Guarding

Slide 152 (of 185)

Slide 153 (of 185)

1910.219(f) Gears, Sprockets,and Chains

Slide 154 (of 185)

• (1) Gears shall be guarded in accordance with one of the following methods:– (i) By a complete enclosure; or– (ii) By a standard guard as described

in paragraph (o) of this section, at least seven (7) feet high extending six (6) inches above the mesh point of the gears; or

– (iii) By a band guard covering the face of gear and having flanges extended inward beyond the root of the teeth on the exposed side or sides. Where any portion of the train of gears guarded by a band guard is less than six (6) feet from the floor a disk guard or a complete enclosure to the height of six (6) feet shall be required.

1910.219(f) Gears

Slide 155 (of 185)

• All sprocket wheels and chains shall be enclosed unless they are more than seven (7) feet above the floor or platform. Where the drive extends over other machine or working areas, protection against falling shall be provided.

1910.219 (f)(3) Sprockets and Chains

Slide 156 (of 185)

• (1) Collars. All revolving collars, including split collars, shall be cylindrical, and screws or bolts used in collars shall not project beyond the largest periphery of the collar.

• (2) Couplings Shaft couplings shall be so constructed as to present no hazard from bolts, nuts, setscrews, or revolving surfaces. Bolts, nuts, and setscrews will, however, be permitted where they are covered with safety sleeves or where they are used parallel with the shafting and are countersunk or else do not extend beyond the flange of the coupling.

1910.219 (i) Collars and Couplings

Slide 157 (of 185)

• (1) Materials– (i) Standard conditions shall be guarded by the use of the

following materials. Expanded metal, perforated or solid sheet metal, wire mesh on a frame of angle iron, or iron pipe securely fastened to floor or to frame of machine.

– (ii) All metal should be free from burrs and sharp edges.

1910.219(m) Standard GuardsGeneral Requirements

Slide 158 (of 185)

• (1) Minimum requirements. – The materials and

dimensions specified in this paragraph shall apply to all guards, except horizontal overhead belts, rope, cable, or chain guards more than seven (7) feet above floor, or platform.

1910.219(o) Approved Materials

Slide 159 (of 185)

• (i) 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; also in construction work and in locations outdoors where extreme cold or extreme heat make metal guards and railings undesirable. In all other industries, wood guards shall not be used.

1910.219(o)(2) Wood Guards

Wood guard

Wood guard

Slide 160 (of 185)

29 CFR 1910.261Paper, Pulp & Paperboard Mills

Application of 29 CFR 1910.212

Slide 161 (of 185)

Hydro Pulper

Slide 162 (of 185)

Fourdrinier

Slide 163 (of 185)

Screen Roll

Slide 164 (of 185)

Screen Cleaning

Slide 165 (of 185)

Threading the Presses (Tailing)

Slide 166 (of 185)

Cooch Carrier Roll Nip Point

Slide 167 (of 185)

Cooch Carrier Roll Nip Point

Slide 168 (of 185)

First Press Nip Point

Slide 169 (of 185)

Press Section / First Dryer

Slide 170 (of 185)

Cylinder Machine Nip Point

Slide 171 (of 185)

Cleaning the Press Roll

Slide 172 (of 185)

Dryers (Front Side)

Slide 173 (of 185)

Dryer (Back Side)

Slide 174 (of 185)

Slide 175 (of 185)

Isolation Guarding

Slide 176 (of 185)

Line Shaft

Slide 177 (of 185)

Incline Belts and Pulleys

Slide 178 (of 185)

Tailing (Threading) the Dryer

Slide 179 (of 185)

Dryer Nip Point

Slide 180 (of 185)

Reel Nip Point

Slide 181 (of 185)

Rewinder Nip Point

Slide 182 (of 185)

Guarded Rewinder

Slide 183 (of 185)

Rotary Cutters

Slide 184 (of 185)

Embosser Nip Point

Slide 185 (of 185)

Nip Point Guarding