Guards
Prevent Access
If Infeasible
Devices
Control Access
1
Requirements of
Safeguards

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Prevent contact
Secure
Protect from falling objects
Create no new hazards
Create no interference
Allow safe lubrication
2
Where Mechanical
Hazards Occur

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Point of operation
Power transmission apparatus
Other moving parts
– Nip points
– Pinch points
– Shear points
– Rotating parts
– Flying parts
3
Training
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Description and identification
of hazards
How they provide protection
How to use safe guards
When to remove
Protocol when safeguards are
missing
4
Methods of
Guarding
Guards
 Devices
 Location/distance
 Feed mechanisms
 Miscellaneous aids

5
Guards

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Barrier to prevent access
to danger
Fixed guards
Interlocks
Adjustable
Self-adjusting
Stock Exit
Stock entering
danger zone
Transparent insert
in front panel
6
Fixed Frame Panel
7
Box Barrier Guard without Inserts
8
Adjustable Panels
Rigid - Adjustable
Fixed - Adjustable
9
Two and Four Panel Barrier Guard
Not considered a safeguard. Are used with safeguarding devices such as two-hand trips,
presence sensing devices, pullback, or restraints. Designed to protect sides of the point of
operation while the front is open for feeding and removing of pieceparts.
10
Three and Five Panel Barrier Guard
Are designed to meet point-of-operation requirements. Rear of machine must
also be guarded when applying front and side guards.
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Interlock Safety Switches
12
Devices

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Presence-Sensing
Radiofrequency
Electromechanical
sensing device
Pullbacks
Restraints
Safety Trip Controls
Two-Hand Controls
Two-Hand Trip
Gates
13
Presence Sensing Device
Transmitters
Receivers
Control Box
Interconnecting Cables
14
Arm-Type Device
Arms
15
Arm-Type Pullback
Pullbacks
16
Overhead-Type Pullback
17
Restraint Device - Arm-Type
Restraint
18
Two-Person Overhead
Sliding Restraint
19
Control Package with Light Curtain
Interface or Two-Hand Control
Control
Box
Light Curtains
on Floor Stands
Two Operator
Stations
Barriers
20
Press brake with two-hand
control sequence
Emergency
Stop
Two-hand
Controls
21
Gate Guards - Type “A” and“B”
22
Location/Distance

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Hazard analysis
Hazards not accessible
Walls
Fences
Height
Stock dimension
Operators station
23
Press Safety Distances
Distance of Opening from Point
of Operation Hazard (inches)
Maximum width of opening
(inches)
1/2 to 1-1/2
1-1/2 to 2-1/2
2-1/2 to 3-1/2
3-1/2 to 5-1/2
5-1/2 to 6-1/2
6-1/2 to 7-1/2
7-1/2 to 12-1/2
12-/12 to 15-1/2
15-1/2 to 17-1/2
17-1/2 to 31-1/2
1/4
3/8
1/2
5/8
3/4
7/8
1-1/4
1-1/2
1-7/8
2-1/8
24
Press Safety Distances (cont’d)

Once a safe distance is calculated,
note the following to right of press.
– Date of measurement
– Stopping time
– Safe distance calculation
– Added distance to allow for normal
deterioration
– Forward most point of operation
– Fixed location of safety device/guard
25
Feeding & Injection
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Automatic feeding
Semi-automatic feed
Automatic injection
Semi-automatic
injection
Robots
26
Robot Safeguarding
Station
Control
Guard
Machine
Safety
Mat
Light
Curtain
Receiver
Robot
Parts
Bin
Parts
Chute
Guard
Light Curtain
Transmitter
Mirror
27
Miscellaneous Aids

Awareness barriers

Shields

Holding tools

Push stick or block
28
Signs for Machinery
OPERATOR
SAFETY PRECAUTIONS
Handout for Anyone Operating This Machine
Before You Operate This Machine You Must
Read and Understand These Safety Precaution
! DANGER
NEVER
Place Your Hands
or Any Part of
Your Body in This
Machine
See Reverse Side for Other Safety Precautions.
29
Signs For Machinery
!
PELIGRO
ARIETE HIDRAULICO Y TROQUEL CIERREN
RESULTARA EN LA PERDIDA
DE DEDOS O DE MEMBROS
SI ESTAN METIDO EN LA
MAQUINA
NUNCA
USW UN PEDAL DE PIE PARA
OPERAR ESTA MAQUINA A
MENOS QUE SE PROVEE Y
MANTIENE UN PROTECTOR DE
SEGURIDA PARA EVITAR QUE
LAS MANOS U OTRAS PARTES
DEL CUERPO ENTREN EN LA
MAQUINA.
NO SE DEBE QUITAR O TAPAR ESTE LETRERO.
VEA L REVES PARA MAS INSTRUCCIONES.
30
Free-Standing shield used around machines
to protect people from flying objects
31
Shield on milling machine
32
Sliding Lathe Shield
33
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