Hazardous Mechanical Motions and Actions
A wide variety of mechanical motions and actions may present hazards to the worker.
Machine Motions
Machine Actions
These can include the movement of rotating members, reciprocating arms, moving belts, meshing gears, cutting teeth, and any parts that impact or shear.
These different types of hazardous mechanical motions and actions are basic in varying combinations to nearly all machines, and recognizing them is the first step toward protecting workers from the danger they present.
The basic types of hazardous mechanical motions and actions associated with machinery are critical to understand for effective machine guarding. These hazards can cause serious injuries if safeguards are not properly designed, maintained, and used.
Hazardous Mechanical Motions include:
- Rotating Motions: These involve parts that turn around a fixed axis. This category includes in-running nip points, which are areas where two rotating parts move toward each other or where a rotating part moves toward a stationary object, creating a risk of pulling in or entanglement.
- Reciprocating Motions: These are back-and-forth or up-and-down movements. They can cause crushing, shearing, or striking injuries as parts move toward and away from workers repeatedly.
- Transversing Motions: These are side-to-side or linear movements across a work area. They can trap or strike workers if they come into contact with moving parts.
Hazardous Mechanical Actions include:
- Cutting: Actions where sharp edges or blades slice through materials. These pose severe risks of lacerations or amputations if workers' hands or limbs come into contact with the cutting element.
- Punching: Pressing or driving a tool through a material, which can cause crushing or penetrating injuries.
- Shearing: The action of two parts moving closely past each other to cut or slice material, similar to scissors. This creates pinch points that can sever fingers or limbs.
- Bending: Forces applied to bend or shape materials, which can trap or crush body parts if caught in the operation.
Related Mechanical Hazards
In addition to these fundamental motions and actions, other related mechanical hazards to consider include:
- Impact Hazards: Sudden striking or hitting motions from machine parts or flying debris can cause blunt force injuries.
- Crushing Hazards: Areas where body parts can be caught between moving parts or between a moving and a stationary object.
- Entanglement Hazards: Loose clothing, hair, or jewelry can get caught in moving parts, especially rotating or in-running nip points.
- Shear Points: Locations where two parts move closely together in opposite directions, creating a risk of cutting or crushing.
- Pinch Points: Points where two parts move together and at least one moves in a circle, presenting a trapping hazard.
Understanding these motions, actions, and related hazards is essential for selecting and applying appropriate machine guards to protect workers effectively.
Knowledge Check Choose the best answer for the question.
1-2. Which of the following is a hazardous mechanical motion?
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