“GENERAL MACHINE SHOP
SAFETY TRAINING”
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PINCH POINTS
Occur between rotating and fixed parts which can
create a shearing, crushing or abrading action.
 RECIPROCATING MOTION
The equipment may entrap a worker between a
moving and stationary object, during the up,
down, back and forth motion.
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TRANSVERSE MOTION
Creates a hazard when the worker is pulled into the
pinch point or shear point or is dragged by the
moving parts into other moving parts.
 CUTTING ACTION (Involves: Rotating,
Reciprocating or Transverse Motions)
Dangers exists at the point of operation where
finger, head, and arm injuries occur and where
flying chips or scrap material can strike eyes or
face.
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PUNCHING ACTION
Results when power is applied to slide for the
purpose of blanking, drawing or stamping
metal or other materials. Danger of this type of
action occurs at the point of operation where the stock
is inserted, held or withdrawn.
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SHEARING ACTION
Applying power to a slide or knife in order to
trim or shear metal or other materials. Hazards
occurs at the point of operation where the stock
is inserted, held or withdrawn.
 BENDING ACTION
Applying power to a slide in order to draw
or form metal or other materials. Hazards
occur at the point of operation where stock is
inserted, held or withdrawn.
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GUARDS
oPhysical barriers that prevent access to danger
areas.
oMust prevent hands, arms, or any part of
the body
or clothing from making contact with dangerous
moving parts.
oShould prevent contact, be secured and well
constructed.
oShould protect from falling objects and contain the
hazard.
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TYPES OF GUARDS
Fixed Guards-Are a permanent part of the machine,
they are not dependent on moving parts to perform
their intended functions.
Interlocked Guards-When opened or removed the
tripping mechanism and or power are automatically
shut off or disengaged, the machine cannot cycle
until replaced.
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Adjustable Guards-Allow flexibility in
accommodating various sizes of stock. Properly
adjusted this guard provides protection from point
of operation hazards.
Self-Adjusting Barriers-As the Operator moves
stock into the danger area, the guard is pushed
away, providing an opening that is only large
enough to admit the stock being used. After the
stock is removed the guard returns to rest position.
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Photoelectric (Optical) Presence Sensing Device-Uses
a system of light sources and controls which can
interrupt the machines operating cycle if the light
field is broken, the machine stops and will not cycle.
This can only be used on machines which can be
stopped before the worker can reach the danger area.
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Presence-Sensing DevicesoEither stops the machine or will not start if
a hand
or any body part is inadvertently placed in the
danger area.
oP-S Devices create a sensing field that detects the
presence of an object larger than an outlined size.
oWhen the signal is obstructed the P-S sends a stop
signal to the machine.
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Radio Frequency (Capacitance) Presence-Sending
Device-Uses a radio beam that is part of the machine
circuit control, when the capacitance field is broken
the machine will stop or not activate.
oThis device can only be used on machines which can
be stopped before the worker reaches the danger
zone.
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Electromechanical Sensing Device-Has a probe or
contact bar which descends to a predetermined
distance when the operator initiates the machine
cycle. If there is an obstacle preventing it from
descending its full predetermined distance, the control
circuit does not actuate the machine.
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Pull Back Device-Uses a series of
cables attached to
the operator’s hands, wrist and or arms. Used
primarily on machines with a stroking action.
oWhen the slide or ram is up the operator is allowed
access to the point of operation, when the slide or
ram is descending a mechanical linkage withdraws
the hands from the point of operation.
oA restraint device uses cables or straps that are
attached to the operators hands at a fixed point
and are adjusted to allow the operators hands travel
within a predetermined safe area.
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*Safety Trip Controls-Are devices that provide a quick
means for deactivating the machines in an emergency
situation.
A pressure sensitive bar, when depressed will
deactivate the machine. If the operator or anyone
slips, trips, loses balance or is drawn toward the
machine. Applying pressure to the bar will stop
operation of machine.
It is position sensitive as it has to be activated by
the operator during an emergency situation,
therefore it’s position is critical to the operator.
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When exposures to hazards cannot be
engineered completely out of the process and
other forms of Administrative procedures
cannot provide additional protection, a
supplementary method of control is Personal
Protective Equipment.
PPE is not a substitute for Engineering or
Administrative Controls.
29 CFR 1910.132 OSHA Standards set
controls for PPE usage.
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Eye and Face Protection
o The employer shall ensure that each affected
employee uses appropriate eye or face protection
when exposed to eye or face hazards from flying
particles, molten materials, liquid chemicals,
acids or caustic liquids, chemical gases or vapors
or potentially injurious light radiation.
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Respiratory Protection
o A respirator shall be provided to each employee
when such equipment is necessary to protect
the health of such employee.
oThe employer shall provide the respirators
which are applicable and suitable for the
purpose intended.
oThe employer shall be responsible for the
establishment and maintenance of a
respiratory protection program, which shall
include the requirements outlined in paragraph
(c) of this section. The program shall cover
each employee required by this section to use a
respirator.
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Head Protection
o The employer shall ensure that each affected
employee wears a protective helmet ( hard hat )
when working in areas where there is a potential for
injury to the head from falling objects.
o The employer shall ensure that a protective helmet
( hard hat ) designed to reduce electrical shock
hazard is worn by each such affected employee when
near exposed electrical conductors which could
contact the head.
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Foot Protection
o The employer shall ensure that each affected
employee uses protective footwear when working
in areas where there is a danger of foot injuries
due to falling or rolling objects, or objects
piercing the sole, and where such employee's feet
are exposed to electrical hazards.
o Protective footwear must comply with any
of the following consensus standards:
ASTM F-2412-2005, ANSI Z41-1999,
ANSI Z41-1991
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Hand Protection
o Employers shall select and require employees to
use appropriate hand protection when
employees' hands are exposed to hazards such as
those from skin absorption of harmful
substances; severe cuts or lacerations; severe
abrasions; punctures; chemical burns; thermal
burns; and harmful temperature extremes.
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An Abrasive Wheel is a grinding tool consisting of
bonded abrasive grains.
Grinding wheels are made of
natural or synthetic
abrasive materials bonded together in a matrix to
form a wheel.
o Numerous shapes; flat disks, cylinders, cups, cones and
wheels with specific cuts & grits.
 Abrasive grains constitute the central component of
any grinding wheel and the hardness and friability of
the grinding materials will significantly affect the
behavior of a given wheel.
 Abrasive wheel hazards that can occur using
abrasive wheels include but are not limited to,
shock, scrapes, cuts, eye injury and loss, finger
injury and loss, hearing loss, head and body
wounds.
o Wheels can break and become dangerous flying
projectiles in a work environment.
o Dust can be a health hazard and employees should
were proper PPE when working on materials that
create large amounts of dust in the operation.
Hazards can be created by external factors;
o Distractions by someone or something else
o Horseplay in or around work area
o Conversations with someone while operating
machinery.
o Reaching across working areas
o Wearing jewelry (rings or necklaces)
o Long hair ( not tied up and back)
o Loose fitting clothing
o Hot sparks
o Gloves
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Mechanical Power Presses are machines that
transmit force to cut, form, or assemble metal or
other materials through tools or dies attached to or
operated by slides.
3 types of
Mechanical Power Presses
o Mechanical
o Hydraulic
o Pneumatic
 A Mechanical Press is a
machine that exerts
pressure to form or shape or cut materials or
extract liquids or compress solids.
 A Press is a mechanically powered machine that
punches, shears, forms or assembles metal or other
materials by means of cutting, shaping or
combination of dies attached to slides or rams.
 A Press consists of
a stationary bed ( or anvil ),
and a slide ( or slides ) having a controlled
reciprocating motion toward and away from the
bed surface, the slide being guided in a defined
path by the frame of the press.
 Major components of
o The Frame
o Motor
o Flywheel
o Crankshaft
o Clutch
o Brake
a Mechanical Press are;
 Main Hazard
o AMPUTAIONS
 Placing hand into point of operations
 Unguarded or inadequately guarded presses
 Deactivating or over-riding safeguards
 Safeguards most commonly used:
o Barrier guards attached to fixed surfaces
o Presence-Sensing devices
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Radio Frequency Sensors
Light Curtains
Pullback Devices
Fixed Guards
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 Robots are machines that load and unload stock,
assemble parts, transfer objects or perform other
tasks.
They can be used to replace humans who were
performing unsafe, hazardous, highly repetitive and
unpleasant tasks.
Robots are used to accomplish many different
types of application functions such as material
handling, assembly, arc welding, resistance welding,
machine tool load and unload functions, painting,
spraying and other functions.
 Industrial Robots are programmable
multifunctional mechanical devices designed to
move materials, parts, tools or specialized
devices through variable programmed motions
to perform task safely.
Robot injuries do not normally occur during
normal operating conditions. But rather under
these conditions:
o During programming
o Program touchup
o Maintenance or Repair
o Testing, Setup or Adjustment.
 During many of
these operations, the Operator,
Programmer or Maintenance Worker may
temporarily be within the robot’s working
envelope where unintended operations could result
in injuries.
 Mechanical hazards include workers :
o Colliding with equipment (Robot’s Arm or
peripheral equipment)
o Being crushed (trapped between the Robot’s Arm
or peripheral equipment)
o Injured by falling objects ( failure of
gripper
mechanisms with resultant release of parts )
Effective Safeguarding of
Robotics
o The proper selection of
an effective robotic
safeguarding system should be based upon a hazard
analysis of the robot’s system use, programming
and maintenance operations.
o Among the factors to be included are the tasks a
robot will be programmed to perform.
Start up
Command or programming procedures
Environmental conditions
Location and installation requirements
Possible human error
Scheduled and unscheduled maintenance
Possible robot and system malfunctions
Normal mode operations
Personnel functions and duties associated with
operation.
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An effective safeguarding system protects not
only the operators but also engineers,
programmers, maintenance workers and
others who work on or with robot’s systems
and could be exposed to hazards with a robot’s
operation.
o A combination of
safeguarding methods maybe
used. Redundancy and backup systems are
especially recommended , particularly if a robot
or robot system is operating in a hazardous
condition or handling hazardous materials.
o The safeguarding devices employed should not
themselves constitute a hazard or curtail
necessary vision or viewing by attending human
operators.
o Personnel should be safeguarded from hazards
associated with the restricted envelope ( space )
through the use of one or more safeguarding
devices.
o Mechanical limiting devices
o Non mechanical limiting devices
o Presence Sensing devices
o Fixed Barriers ( which prevent contact with
moving parts )
o Interlocked barrier guards
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 The intent of
Lockout – Tagout is to safeguard
employees from the unexpected startup or
machinery or equipment or release of hazardous
energy.
 Lockout is the placement of
a lockout device on an
energy isolation device ( circuit breaker, slide gate,
line valve, disconnect switch, etc. )
o A lockout device utilizes a positive means such as a
lock to hold an energy isolating device in a safe
position and prevent re-energization of the machine.
o The lockout device must be substantial enough to
prevent removal without the use of excessive force or
unusual techniques.
o Lockout shall be used unless the employer can
demonstrate that the utilization of a tagout system
will provide full employee protection.
 Tagout is the placement of a tagout device ( tag or
other prominent warning device ) on an energy
isolating device to indicate that the energy isolating
device and the equipment being controlled, may not be
operated.
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The tagout device shall be non-reusable, attached by
hand, self-locking and non-releasing with a minimum
unlocking strength of no less than 50 pounds, must be
equivalent to an all environment tolerant nylon cable
tie.
April 13, 2011
A STAR YALE UNIVERSITY SCIENCE STUDENT WAS KILLED EARLY TODAY IN AN INDUSTRIAL ACCIDENT AT A CAMPUS MACHINE SHOP WHERE
EQUIPMENT FOR EXPERIMENTS WAS CONSTRUCTED.
Yale Vice President Linda Koch said the student, Michele Dufault of Scituate, Mass., died after a "terrible accident involving a piece of equipment
in the student machine shop."
Sources told the New Haven Register that the student's hair got caught in a spinning lathe and it pulled her in.
The university said in a statement that the accident occurred at the Sterling Chemistry Laboratory, but provided no details of what happened.
Dufault was an astronomy and physics major who was expected to graduate with a bachelor's of science degree this spring.
David Johnson, the machine shop instructor, could not be reached for comment. Yale's chemistry department online says it has a state-of-the-art
machine shop to allow students to construct or modify research instrumentation. Access is strictly limited to those who have completed the shop
course. The laboratory was closed today, with all classes and labs in the building cancelled.
"By all reports, Michele was an exceptional young woman, an outstanding student and young scientist, a dear friend and a vibrant member of this
community. We will find ways in the next day to gather to celebrate her life and grieve this loss," Koch said.
A federal official says a Yale University student Michele Dufault died after her hair was pulled into a piece of equipment in a chemistry lab
machine shop.
Dufault's uncle, Frederick Dufault, said he spoke with her parents this morning and they were heading to the university. He did not have any
information on her funeral arrangements.
She was an exceptional student and a wonderful person, just the best kid in the world. The world is going to be sadder place without her. I'm just
still in shock," Frederick Dufault said. "She was gifted in many areas not just science, she was a gifted musician, she was a gifted athlete and did
crew, she was just a super talented kid just beyond belief, it's a loss not only for her family but for the world."
Dufault was a member of the "Yale Drop Team," an organization that allows students to perform reduced-gravity experiments with NASA programs.
Dufault was a summer 2010 student fellow for the Woods Hole Oceanographic Institute in Woods Hole, Mass. Dean of academic programs, Jim Yoder
said she participated in a highly selective program for young scientists.
"She worked closely with WHOI scientists who design and operate robotic vehicles to make remote chemical and other measurements in the ocean.
The WHOI community is deeply saddened by the loss of such an intelligent young woman with such high potential," Yoder said.
In February 2009, Dufault participated in a workshop to engage young girls to become interested in science. Dufault told the Yale Daily News: "It's
nice for the girls to be able to ask questions and say what they want without being judged by guys," Dufault said. "Almost all of the volunteers and
scientists involved with this program are women—showing the girls that women can succeed in the sciences. I wish I had that opportunity at their
age."
Dufault attended high school at the Noble and Greenough School in Dedham, Mass. The head of school, Robert Henderson Jr. said her successes
touched almost every aspect of the school's program.
"Dufault was an extraordinary young woman, one of the most precocious students who her teachers ever encountered," said Henderson. "She
was simply brilliant. Her mind, her sense of curiosity, her perceptiveness, her sensitivity, and her enjoyment of what she did were
extraordinary. She was a true intellectual."
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 BE AWARE OF THE DANGERS OF THE
MACHINE YOU ARE OPERATING
 USE ALL REQUIRED SAFETY EQUIPMENT
 ENSURE GUARDS ARE IN PLACE AND
FUNCTIONAL AT ALL TIMES
 HAVE A PRE-OPERATIONAL CHECKLIST
FOR EQUIPMENT’S SAFETY FEATURES
FOLLOW ALL SAFETY REQUIREMENTS IN
PLACE IN THE SHOP YOU ARE WORKING IN.
DO NOT USE AN IPOD TO MUSIC WHILE
OPERATING MACHINERY