English
uses. See the "Maintenance, Repair and
Storing" section of these Safety
Precautions. Remember that the risk of
a brush or forest fire is greater in hot or
dry conditions.
Warning!
Some STIHL power tools
are equipped with a cata-
lytic converter, which is
designed to reduce the
exhaust emissions of the
engine by a chemical
process in the muffler. Due to this proc-
ess, the muffler does not cool down as
rapidly as conventional mufflers when
the engine returns to idle or is shut off.
To reduce the risk of fire and burn inju-
ries when using a catalytic converter,
always set your power tool down in the
upright position and never locate it
where the muffler is near dry brush,
grass, wood chips or other combustible
materials while it is still hot.
Reactive Forces
Warning!
Reactive forces may occur any time the
chain is rotating.The force used to cut
wood can be reversed and work against
the operator. If the rotating chain is sud-
denly stopped by contact with any solid
object such as a branch or is pinched,
the reactive forces may occur instantly.
These reactive forces may result in loss
of control, which, in turn, may cause
personal injury. An understanding of the
causes of these reactive forces may
help you avoid the element of surprise
and loss of control.
12
Because of the design of the pole
pruner, the reactive forces experienced
when working with it are generally not as
severe as those encountered with a
chain saw. Nevertheless, you should
always maintain a proper grip and good
footing to control the power tool when
you experience such forces.
The most common reactive forces are:
–
kickback,
–
pushback,
–
pull-in.
Kickback
Kickback may occur when the moving
saw chain near the upper quadrant of
the bar nose contacts a solid object or is
pinched.
The reaction of the cutting force of the
chain causes a rotational force on the
chain saw in the direction opposite to the
chain movement. This may cause the
bar to move upward.
To Avoid Kickback
The best protection from kickback is to
avoid kickback situations:
1.
Be aware of the location of the guide
bar nose at all times.
2.
Never let the nose of the guide bar
contact any object. Do not cut limbs
with the nose of the guide bar. Be
especially careful near wire fences
and when cutting small, tough
limbs, which may easily catch the
chain.
3.
Cut only one limb at a time.
A = Pull-in
Pull-in occurs when the chain on the
bottom of the bar is suddenly stopped
when it is pinched, caught or encounters
a foreign object in the wood. The
reaction of the chain pulls the saw
forward.
Pull-in frequently occurs when the chain
is not rotating at full speed before it
contacts the wood.
To Avoid Pull-in
1.
Be alert to forces or situations that
may cause material to pinch the
chain at the bottom of the bar.
2.
Always start a cut with the chain
rotating at full speed.
A
HT 56 C