Kickback And Other Reactive Forces; Reactive Forces; Kickback - Stihl HTA 135 Owner's Instruction Manual

7 Kickback and Other Reactive Forces

– Maintain a clearance of at least
– Before working with less
7 Kickback and Other Reactive Forces
7.1

Reactive Forces

WARNING
￭ Reactive forces may occur any time the chain is rotating.
Reactive forces can cause serious or fatal personal injury.
￭ The powerful forces used to cut wood can be reversed and
work against the operator. If the rotating saw chain is
suddenly and significantly slowed or 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 serious or fatal injury.
– An understanding of the causes of these reactive
forces may help you avoid the element of surprise
and loss of control. Surprise contributes to
accidents.
￭ 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, always maintain a proper grip and
good footing to control the pole pruner when you
experience such forces.
The most common reactive forces are:

– Kickback

0458-698-8621-A
50 ft. (15 m) between the pole
pruner (including any branches
it is contacting) and any
electrical line carrying live
current.
clearance, contact your electric
utility and make sure the current
is turned off.
– Pull-in
– Pushback
7.2 Kickback
7.2.1 Kickback
WARNING
￭ Kickback may occur when the moving chain near the
upper quadrant of the bar nose contacts a solid object or
is pinched.
￭ When this occurs, the energy driving the chain can create
a force that moves the pole pruner in a direction opposite
to the chain movement at the point where the chain is
slowed or stopped. This may cause the bar to move
upward.
7.2.2 To Avoid Kickback
The best protection from personal injury that may result 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.
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