October 2 Flashcards
True or False: Any machine part, function, or process which may cause injury must be safeguarded
True - When the operation of a machine or accidental contact with it can injure the operator or others in the vicinity, the hazards must be either controlled or eliminated
General Requirements for all Machines - comparable to what?
the general duty clause but for all machines
General Requirements for machines - types of guarding - protect from hazards as those created by :
point of operation, ingoing nip points, rotating parts, flying chips and sparks
General Requirements for machine guards:
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
Point of Operation definition
Point of Operation is the area on a machine where work is actually being performed upon the material being processed
Point of Operation Guarding
ii. The point of operation of machines whose operation exposes an employee to injury, shall be guarded. The guarding device shall be in conformity with any appropriate standards therefore, or, in the absence of applicable specific standards, shall be so designed and constructed as to prevent the operator from having any part of his body in the danger zone during the operating cycle.
Point of Operation guarding - special hand tools
iii. Special hand tools for placing and removing material shall be such as to permit easy handling of material without the operator placing a hand in the danger zone
True or False: Special Hand tools for placing an removing material can be used in lieu of other guarding required by this section
False - they can only be used to supplement protection provided
concerns with E-stops
- E-stops must NOT be used to routinely control processes
- E-stops must be periodically tested
- E-stops must be accessible
Exposure of blades
When the periphery of the blades of a fan is less than 7 feet above the floor or working level, the blades shall be guarded. The guard shall have openings no larger than (1/2) inch
Anchoring fixed machinery
machines designed for a fixed location shall be securely anchored to prevent walking or moving
Dangerous moving parts in three basic areas require safeguarding:
- Point of operation
- Power Transmission Apparatus - all components of the mechanical system which transmit energy to the part of the machine performing the work (flywheels, pulleys, belts, couplings, chains, cranks, gears).
- Other moving parts - all parts of the machine which move while the machine is working (including reciprocating, rotating, and transverse moving parts, feet mechanisms, and auxiliary parts of the machine
Safeguard must meet these minimum general requirements:
- prevent contact
- be securely attached
- protect from falling objects
- create no new hazards
- create no interference
- allow safe lubrication
what factors affect how to safeguard a machine?
type of operation, size/shape of stock, method of handling, physical layout of work area, type of material, and production requirements/limitations
5 classifications of safeguards
- guards
- devices
- location/distance
- potential feeding and ejection
- miscellaneous aids
types of guards
- fixed ( guard on bike chain)
- interlocked (interlock on microwave, washing machine)
- adjustable (guard on a ban saw)
- self-adjusting (guard on circular saw)
types of devices
- presence sensing (photocell, light curtain)
- Pullback
- Restraint - prevents you from getting into point of operation
- safety controls (e.g., two-hand controls, trips)
- gates (interlocked gats, covers, etc.)
difference between two hand trip and two hand control
- two-hand trip - push 2 buttons and it trips machine (goes through a cycle)
- two - hand control - hold 2 buttons and machine goes until you let at least 1 go
Potential feeding and ejection methods to improve safety for the operator:
- automatic feed
- semi- automatic feed
- automatic ejection
- semi-automatic ejection
- robot
miscellaneous aid
- awareness barriers
- miscellaneous protective shields
- hand-feeding tools and holding fixtures
Point of Operation guarding:
- where machine interfaces with materials/parts
- should be designed to allow work to enter but keep operator out
Nip points are created by:
- two or more points rotating in opposite direction
- parts rotating tangentially to each other
- parts rotating close to a fixed part
- may not need to guard entire wheel, but just the nip point
“Push Stick”
a narrow strip of wood or other soft material with a notch cut into one end and which is used to push short pieces of material through saws.
“Block”
short block of wood, provided with a handle similar to that of a plane and shoulder at the rear end, which is used for pushing short stock over revolving cutters.
