Machine Safeguarding for supervisors and lead hands

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Machine
Guarding
Julian Kalac, P.Eng
June 11, 2013

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Scenario
• Printing press
• 42 year old operator with 20 years exp.
• Pinch point – 150psi
• Distance from pinch point to safety stop
– 8 feet
• No guards in place
• Operator goes to remove a paper jam……..

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Result
• Hospitalized for 1 week
• Rehabilitation for 4-6 months
• Severed tendons & nerves
• Laceration to bone
• Missing nerves & tendons
• Loss of sensation
• Loss of range or motion
• Finger tips permanently bent
*These are only
The physical problems

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Any machine part, function, or
process which may cause
injury must be safeguarded
Rule to Remember

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New Guards
for Printing Press

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Types of Hazardous Mechanical
Motions
and Actions
• Rotating (including in-running nip points)
• Reciprocating
• Transverse
• Cutting
• Punching
• Pinching
• Shearing
• Bending

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Rotating Motion
• Common rotating mechanisms
– Collars
– Couplings
– Cams
– Clutches
– Flywheels
– Shaft ends
– Spindles
– Horizontal/vertical shafting

18. Dangerous moving parts in these basic areas require safeguarding:
1. Point of operation
2. In running nip points
3. Pinch points
4. Power transmission
5. Other moving parts
Where Dangerous Mechanical Hazards Occur

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Types of Machine Guards
• Guards
– Fixed
– Interlocked
– Adjustable
– Self-adjusting
• Devices
– Presence sensing
• Photoelectrical (optical)
• Radio frequency (capacitance)
• Electromechanical

20. Machine Guards
• Machines guards are there to protect from
exposed hazards
• Guarding MUST never be removed unless
under supervision and locked out
• If a Guard is missing notify your supervisor
immediately
• Never bi-pass the guarding!
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Types of Machine Guards
• Devices (cont’d)
– Pullback
– Restraint
– Safety controls
• Safety trip control
– Pressure-sensitive body bar
– Safety trip rod
– Safety tripwire cable
• Two-hand control
• Two-hand trip
– Gates
• Interlocked
• Other

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Fixed Guard
Provides a barrier - a permanent part of the
machine, preferable to all other types of guards.

23. Parts rotating in opposite direction
In-running nip point hazards
Rotating and tangentially moving
parts
Rotating Parts
Point of contact between a
chain and a sprocket

24. Examples of 3 Types of Motion
Rotating and fixed parts
Transverse motion
Rotating and tangential motion

25. Grinder Safety
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26. Grinder Safety (cont)
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27. Cutting Saws
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Point of contact Blade not guarded

28. Max Gap Allowable gaps Grinder

29. Guarded vs Ungarded Saw
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30. PINCH POINTS

31. LAMINATOR GUARDING
Interlocked Guarding
Mesh Guarding

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Adjustable Guard
Provides a barrier which may be adjusted to
facilitate a variety of production operations.
Bandsaw blade
adjustable guard

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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

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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

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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

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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

37. Example #1
Slitter guarding using guards

38. Front view of guard

39. Example #1 SLITTER GUARDING USING MECHANICAL
GUARDS

40. Example #2
Slitter guarding using light curtains

41. Example #2
Slitter guarding using light curtains

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Machine Safety Responsibilities
• Management
– ensure all machinery is properly guarded
• Supervisors
– train employees on specific guard rules in their areas
– ensure machine guards remain in place and are functional
– immediately correct machine guard deficiencies
• Employees
– do not remove guards unless machine is locked and tagged
– report machine guard problems to supervisors immediately
– do not operate equipment unless guards are in place

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Training Questions
• Why must machines be guarded?
• What are the machine hazards ?
• When can you remove a guard?
• What to do if a guard is missing or
damaged?

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Any machine part, function, or
process which may cause
injury must be safeguarded
Rule to Remember

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QUESTIONS???