safety unit 5 machine guarding
"Ring test"
Good wheel portions will "ring" like a bell Cracks will sound "dead"
CPL (Compliance)- 2-1.25
If material is such a size and the operators hand are not closer than 4 inches, its considered a safe guard (not in standards)
hot forming machinery
put metal into furnace and got it red hot
stroking selector
supply a means of selecting OFF, INCH, SINGLE STROKE, or CONTINUOUS with the clutch/brake control
die
the complete tooling component used for cutting, forming, or assembling material within its point of operation
slide
- the main reciprocating press component member. may be called a ram, plunger, head, or platen
uses adjustable guards
-band saws
uses self adjustable guards
-mitre saws -jointer -table saws -circular saws -radial arm saws
Safety Trip Controls
Body Trip Bars Hand/Arm Trip Bars Tripwire Cables Positioning Critical Adjustment Critical Maintenance Critical Training Critical Manual Reset Needed Must Stop Machine Immediately
part revolution
Can disengage clutch at any point along the cycle
full revolution
Cannot disengage clutch until ONE complete stroke is made
roll formers and calendars
Machines which are capable of producing a bend across the width of a flat piece of metal by means of one or more rotating dies or rolls operated by safe interlock switch
press brakes
Metal working machine that forms parts through the use of dies attached to a plate ram or slide and a die bed. Primarily used to bend and form sheet metal but can also be used for punching, trimming, corrugating, and notching are the hardest machine to guard -their dies are not cutting, they are bending the shear
Gate 1. Type A 2. Type B
Movable barrier device which protects the operator at the point of operation before the machine cycle can be started; think of garage door; 2 types
Two-Hand Control
Needs Constant Pressure Needs Concurrent Pressure Positioning Critical Adjustment Critical Maintenance Critical Training Important Must Stop Machine Immediately
true
OSHA says flywheels 7 feet or less above the ground shall be guarded....
Presence-Sensing
Photoelectric Radiofrequency Electromechanical
Tongue guard
Prevent sparks and material from coming back around the wheel and out from the top 1/4''
Adjustable guards
Provides a barrier which may be adjusted to facilitate a variety of production operations Accommodate various sizes of stock May require additional operator training are typically used on
Self- adjusting guards
Provides a barrier which moves according to the size of the stock entering the danger area Accommodate various sizes of stock May require additional operator training
ANSI B11.10 Safety of Machinery- General Requirements and Risk Assessment
Risk assessment recommended and introduces concept of prevention through design
enclosure
Safeguarding by fixed physical barriers mounted on or around a machine to prevent access to the moving parts
point of operation
The area on a machine where material is positioned for processing or where work is actually being performed on the material
Two Hand Trips
Used of full revolution presses with anti-repeat features must be placed far enough from the point of operation to make it impossible for the operators to move their hands from the trip buttons into the point of operation before the first half of the cycle is completed
Restraint Devices
Uses Cables or Straps Affixes to Hands May Need Feeding Tools Adjustment Critical Positioning Critical Maintenance Critical Training Critical
Pullback Devices
Utilizes a series of cables attached to the operator's hands, wrists, and/or arms
belt sanders
finish stock by using a coated abrasive surface to remove material not much of a guard on them hard woods- dust exposure
Type B gate
gate comes down hits interlock switch and tells the machine go, the ram comes down. When the ram starts back up the ram goes back up with it; can ONLY be used on a part revolution
Type A gate
gate stays down entire cycle, and then the ram comes down and hits. After the ram goes back up, the gate will go back up; can be used on full and part revolution
1910.212
general requirements
Awareness Devices
generate a noticeable (distinctive by sound or intensity) audible or visual signal to warn of an approaching or present hazard
roll formers
go horizontal
calendars
go vertical
safe holding
going away from location
expanded metal
has to be 1/2'' holes so you can't get fingers in
spreader
helps reduce from pinching the blade
airline hydraulic cylinder
hydraulic
power transmission
includes all mechanical parts - such as gears, cams, shafts, pulley, belts clutches, brakes, and rods - that transmit energy and motion from a source of power to equipment or a machine
drill press
is a wood cutting machine that uses a multiple-cutting-edged rotating tool to remove wood and produce a hole in the stock
milling
is the machining process of bringing metal into contact with a rotating multi-edged cutter
hostage controls
keeps operator away from machine
"press"
means a mechanically or hydraulically powered machine that shears, punches, forms or assembles metal or other material by means of cutting, shaping, or combination dies attached to slides
Fly wheel
mechanical
reciprocating
moves left or right and north and south
Emergency Stop Devices
must remove all power to the entire machine and must be sustained until a full reset
continuous
no manual feeding
cold forming machinery
not heating the metal
uses interlock guards presence sensing
only on part revolution
1910.219
power transmission
uses fixed guards
power transmission
secondary operation
press machine operation in which a pre-worked part is further processed
stop control
provide a red STOP button with the clutch/brake control system
nip point
rollers=
Type C standards
standards are known as machinery-specific safety standards and contain guidelines that are germane to certain specific machine types
Type B standards
standards deal with safety aspects or safeguards that are applicable to many machine types
brake
the mechanism used on a mechanical power press component to stop and/or hold the slides, either directly or through a gear train, when the clutch is disengaged
antirepeat
the part of the clutch/brake control system designed to limit the press to a single stroke if the actuating means is held or stuck on operate
bolster plate
the plate attached to the top of the bed of the press component; it has drilled holes or T-slots for attaching the lower die or die shoes
feeding
the process of placing or removing material within or from the point of operation
blotter
thicker paper, to cushion the wheel for cutting
Type A standard
this standard identifies basic concepts, principles for design and general aspects that are applicable to all machinery
pedestal grinders, bench grinders and surface grinders
types of grinders
punch press
usually cold forming machinery
location
when a hazard is physically inaccessible under normal operating conditions or permitted only if the other precautionary restrictions can be met
guarding abrasive wheel
**Wheel guard DOES NOT have to protect the entire wheel
guard
A barrier designed for hazard control at the point of operation
true
ANSI says flywheels need to be 8 feet above ground should be guarded
jointers
face or flatten wood and are used primarily to joint small pieces of material done for edges
distance controls
3'' away from machine
table saws
A machine with a circular saw blade which is mounted under a table and only a portion of the blade extends above the table top mostly enclosed
device
A mechanism or control designed for safeguarding at the point of operation
mechanical shears
A metal working machine that is used primarily for shearing or cutting sheet metal Ram moves a nonrotary blade at a constant rate past the edge of fixed blade Can be mechanical or hydraulic with a full or part revolution clutch
Grinding machines
A metal working machine which uses an abrasive wheel against the metal surface causing a change in the surface or shape of the metal
mitre saws
A saw used to make accurate crosscuts and miters in a workpiece Used to an angle on wood -example: door trim Common in construction industry Majority of the time cross cutting is used
ANSI B11.19 Performance Criteria for Safeguarding
Addresses general safeguarding options such as guards, safeguarding devices, awareness devices as well as performance requirements for safe work procedures
safeguarding
Any means of preventing or controlling personnel from coming in contact with the moving parts of machinery or equipment that would potentially cause physical harm
radial arm saws
The operator cuts the wood stock by pulling the saw towards them usually cross cutting for the most part
safety blocks
They disconnect the clutch-and motor-control circuits when blocks are removed from their storage pockets
Complementary Equipment
devices or methods used to ensure or augment the proper operation of safeguarding
band saws
a saw consisting of a continuous band of metal with teeth that rides on two wheels can make curved cuts Horizontal are commonly used in metal work, will be using an oil or water based coolant to protect the saw
inch
an intermittent motion imparted to the slide (on machines using part-revolution clutches) by momentary operation of the inch-operating means. Operation of the inch-operating means engages the driving clutch so that a small portion of one stroke or indefinite stroking can occur, depending on the length of time the inch-operating means is operated; used by the die setter for setup of dies and tooling
primary operation
any preliminary press machine operation with material to be subsequently processed
Fixed guards
are a permanent part of the machine and not dependent upon moving parts to perform its intended function. Provides a barrier and is preferable to all other types of guards
Guards 1. Fixed guards 2. Interlocked guards 3. Adjustable guards 4. Self-Adjusting guards
are barriers which prevent access to danger areas, there are four general types:
Interlocked guards
are designed to automatically shut off or disengage the machine if the guard is opened or removed
lathes
are used for shaping round parts, such as table legs. Two types are used in the woodworking industry: manually operated or CNC operated First hazard- at the point of operation Chuck holds the part in place Coolant, oil or water will come down to cool the parts. If no cover, it will shoot out the coolant out on the floor or such and cause a hazard
planers
are woodworking machines used to dress and size rough-sawed lumber on one or more sides
cross cutting
cutting the wood in opposite way the grain is going
ripping
cutting the wood in the way of the grain on the wood, the wood can pinch and it could cause a kick back
Safeguarding Device
detects or prevents inadvertent access to a hazard