Pull-In; Pushback - Stihl HTA 50.0 Instruction Manual

7 Kickback and Other Reactive Forces
7.3

Pull-in

WARNING
￭ Pull-in occurs when the chain on the bottom of the bar is
suddenly stopped or significantly slowed when it is
pinched, caught or encounters a foreign object in the
wood. The reaction of the chain pulls the pole pruner
forward.
￭ Pull-in usually occurs when the chain is not rotating at full
speed before it contacts the wood.
￭ To reduce the risk of pull-in:
– Be alert to forces or situations that may cause
material to pinch the chain at the bottom of the bar.
– Always start a cut with the chain rotating at full
speed.
7.4

Pushback

0458-813-8621-A
WARNING
￭ Pushback occurs when the chain on the top of the bar is
suddenly stopped or significantly slowed when it is
pinched, caught or encounters a foreign object in the
wood. The reaction of the chain may drive the pole pruner
rapidly straight back toward the operator.
￭ Pushback usually occurs when the top of the bar is used
for cutting.
￭ To reduce the risk of pushback:
– Be alert to forces or situations that may cause
material to pinch or bind the top of the bar.
– Do not cut more than one limb at a time.
– Do not twist the bar when withdrawing it from an
underbuck cut because the chain can pinch or bind.
English
19