Safeguard Design And Mechanism.docx

SAFEGUARD DESIGN AND MECHANISM What is a safeguard? A safeguard is a solution or a combination of solutions that eliminate or reduce the risk of exposure to hazardous moving parts or other harmful conditions. Safeguards range from fixed barrier guards (most effective) and safeguarding devices to safe work procedures and personal protective equipment (least effective). A comprehensive risk assessment will determine which safeguards are most effective. A good rule to remember is: Any machine part, function, or process which many cause injury must be safeguarded. 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.

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Fixed Guard – provides a barrier, permanent part of the machine, preferable to all other types of guards Interlocked Guard – when this type of guard it opened or removed, the tripping mechanism and/or power automatically shuts off or disengages, and the machine cannot cycle or be stated unless the guard is back in place Adjustable Guard - provides a barrier which may be adjusted to facilitate a variety of production operations Self-Adjusting Guard – provides a barrier which moves according to the size of the stock entering the danger area

2. Safeguarding Devices There are many ways to safeguard machines! Determine the appropriate safeguarding method. Consider: o o o o o

The type of operation and material The size or shape of stock The method of handling The physical layout of the work area Production requirements/limitations

These limit or prevent access to the hazardous area. These can be presence-sensing devices, pullback or restraint straps, safety trip controls, two-hand controls, or gates. 

Classification of Safeguards There are six general ways to safeguard machinery and equipment:  Barrier guards  Safeguarding devices  Location Awareness means  Training and procedures  Personal protective equipment 1. Barrier Guards These are physical barriers that prevent contact. They can be fixed, interlocked, adjustable, or selfadjusting.

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Pullback Devices are devices which utilizes a series of cables attached to the operator’s hands, wrists, and/or arms. This is primarily used on machines with stroking action. It allows access to the point of operation when the slide/ram is up, but withdraws hands when the slide/ram begins to descend Restraint Devices use cables or straps attached to the operator’s hands and a fixed point. They must be adjusted to let the operator’s hands travel within a predetermined safe area. Hand-feeding tools are often necessary if the operation involves placing material into the danger area. Safety Controls include tripwire cables, twohand control, etc. o Safety tripwire cables are a device located around the perimeter of or near the danger area. The operator

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must be able to reach the cable to stop the machine. o Two-hand control means the machine requires constant, concurrent pressure in order to activate. The operator’s hands must be at a safe location, on the control buttons, and at a safe distance from the danger area while the machine completes its closing cycle. Gates are movable barrier devices which protect 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.

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Another method to protect workers from mechanical hazards is to 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. It is important to maintain a safe distance from the danger area at all times. Machinery may be safeguarded by location if the distance to dangerous moving parts is greater than 2.4 meters (8 feet) from any floor, walkway, access platform, or service ladder. Any work on the machine must be performed using lockout.

4. Training and Procedures Also known as administrative controls, training, supervision, and procedures are near the low end of the hierarchy of protection because their effectiveness depends on human factors such as adequate training and supervision. Lockout is an example of such a procedure. 5. Personal Protective Equipment Personal protective equipment may have to be used even when other machine hazards are effectively safeguarded. In some cases, such as operating a powered forging hammer, the only protection available to the operator, besides training and safe

work procedures, may be eye and face protection, hearing protection, and hand protection. REFERENCE [1]

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Gibson. (2014, December 8). Methods of Machine Safeguarding [Web log post]. Retrieved from https://www.gibsonins.com/blog/methods-of-machinesafeguarding Safeguarding Machinery and Equipment (General Requirements). (n.d.). Retrieved from https://www.worksafebc.com/en/resources/healthsafety/books-guides/safeguarding-machineryequipment-bk101?lang=en Environmental Health & Safety. (n.d.). Retrieved from https://www.ehs.ucsb.edu/general-safety/machineguarding Basics of Machine Safeguarding. (n.d.). Retrieved from https://www.osha.gov/Publications/Mach_SafeGuard/ch apt1.html