Читать книгу Chainsaw Manual for Homeowners - Brian J. Ruth - Страница 21

After touching the upper tip of the guide bar, the kickback motion has started.

The downward motion of the chain around the saw nose starts the saw rotating clockwise.

The speeding chain may strike the operator in the head or shoulder. The saw in this photo is turned off.

KICKBACK PROBLEM:

Kickback occurs if there is an unexpected or sudden contact with wood in the upper quadrant of the bar nose.

This saw is liable to kick back when the upper part of the tip meets the wood.

KICKBACK SOLUTION:

Pay attention to where the bar nose is. The upper quadrant of the tip should not be touching the wood. And cut with full throttle in a slow, steady, controlled motion.

Kickback Danger Zone

KICKBACK PROBLEM:

If you stand directly in line with the guide bar, and your saw does kick back, you are almost guaranteeing an accident.

KICKBACK SOLUTION:

Always position yourself so you are not in line with the guide bar, as shown at left below. If the saw does kick back for whatever reason (center photo), it will bypass your head and shoulders (right).

Stand off slightly to the side of the cut.

A saw can kick back so quickly that you will not have time to react.

If you are standing to the side, the saw will bypass your head and shoulders. The saw in this photo is turned off.

KICKBACK PROBLEM:

Kickback can occur when the cutters of the chain bite too much wood and cannot cut it. Two things can cause this:

■ The depth gauges in the chain are too low, exposing too much cutter. (See the sharpening information in Chapter 6, here.)

■ The depth gauges are not rounded, causing them to bite.

KICKBACK SOLUTION:

■ Use a depth-setting gauge to file the depth gauges (see Chapter 6).

■ Round off the depth gauges.

■ Have your chainsaw sharpened by a professional.

KICKBACK PROBLEM:

Kickback can occur if you strike a branch that can move, a small twig, rock, or nail.

Cutting small branches that move when the saw hits them can cause kickback.

KICKBACK SOLUTION:

Do not cut small branches that can move unless you can reach the stable base of the branch where it meets the tree trunk.

Kickback is less likely if you trim small branches near the tree trunk.

Tip can contact trunk. Better to turn around and cut from other side, as shown above.

WARNING

Avoid situations that can cause kickback:

Top or blade nose touches bottom or side of kerf during reinsertion

Blade nose strikes another object

WARNING

Protecting yourself from kickback:

• Keep your left arm as straight as possible.

• Keep your left hand behind the guard/chain brake.

• Keep your left thumb wrapped opposite your fingers.

• Do not stand directly in line with the guide bar but slightly to the left.

• Wear your personal protective equipment.