Different Types of Machine Guards

1. 1.       Fixed
2. 2.       Interlocked
3. 3.       Adjustable
4. 4.       Self-adjusting

Fixed Machine Guards

The guard is stationed permanently on the machine. The guard is not dependent on the moving parts for it to function. Fixed guards may be made of sheet metal, wire cloth, screen, bars, plastic or anything that is substantial enough to withstand the impact it receives as well as endure for prolonged usage.

Pros:

• Relatively simple
• Constructed to suit various specific applications
• In-plant construction can be possible
• Provide maximum protection
• Only requires less maintenance
• Used in high production or for prolonged use

Cons:

• Interfere with visibility
• Limited to certain operations
• When machine needs adjustment, it is often times require to be removed, thereby the worker will need to have other means of protection

Interlocked Machine Guards

This type of guard functions (when opened or removed), the tripping mechanism or power automatically shuts off or disengages. The moving parts of the machine are stopped and the machine does not work until the guard is put back in place. This type of guard may use electrical, mechanical, hydraulic or pneumatic power or a combination of these to work.

Pros:

• Provides maximum protection
• Allows access to machine for removing jams without consuming too much time during removal like that of fixed guards.

Cons:

• Needs careful adjustments and maintenance
• Easy to disengage

Adjustable Machine Guards

This type of machine guard provides a barrier that can be adjusted to facilitate several machine operations.

Pros:

• Easy to construct to suit certain applications
• Adjusted to accept different sizes of stock

Cons:

• Protection may not be fully completed where the hands may contact the danger zone
• Requires frequent maintenance or adjustments
• Can be ineffective if set by the operator
• Interferes with visibility

Self-Adjusting Machine Guards

The guards’ opening is based by the movement of the stock – so if the operator moves the stock or material into the danger zone, the guard is then pushed away which provides an opening large enough to take the machine. As soon as the material is removed, the guard then returns to its rest position.

The guard protects the handler or operator by placing the barrier between the operator and the danger zone. It is made of plastic, metal or other substantial material and these types of guards have different degrees of protection.

Pros:

• Readily available in stores

Cons:

• Does not provide maximum protection
• Interferes with visibility

Needs frequent adjustment and maintenance