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154 Machine Safeguarding: Basic
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Hazards of Moving Parts

Introduction

Crushed hands and arms, severed fingers, blindness—the list of possible machinery-related injuries is as long and horrifying. It seems there are as many hazards created by moving machine parts as there are types of machines. Machine guards are essential for protecting workers from needless and preventable injuries.

Good machine safeguarding makes it very difficult for anyone to be exposed to the danger zone.

A good rule to remember is: When the operation of a machine or accidental contact with a machine can injure the operator or others in the vicinity, the hazards must be either controlled or eliminated.

This course describes the various hazards of mechanical motion and presents some techniques for protecting workers from these hazards. General information covered in this chapter includes -- where mechanical hazards occur, the hazards created by different kinds of motions and the requirements for effective machine guards, as well as a brief discussion of non-mechanical hazards.

Any machine part, function, or process which may cause injury must be machine guarded.

Where Mechanical Hazards Occur

Dangerous moving parts in three basic areas require machine safeguarding:

The point of operation: the point where work is performed on the material, such as cutting, shaping, boring, or forming of stock.

Power transmission apparatus: all components of the mechanical system that transmit energy to the part of the machine performing the work.These components include flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears.

Other moving parts: all parts of the machine which move while the machine is working. These can include reciprocating, rotating, and transverse moving parts, as well as feed mechanisms and auxiliary parts of the machine.

Knowledge Check Choose the best answer for the question.

1-1. When the operation of a machine or accidental contact with a machine can injure the operator or others in the vicinity, _____.