OPERATING
English
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17
Reactive force
A reactive force is always present when cutting. The force
pulls the machine in the opposite direction to the chain
rotation. Most of the time this force is insignificant. If the
chain is pinched or stalled the reactive force will be strong
and you might not be able to control the power cutter.
Never move the machine when the cutting equipment is
rotating. Gyroscopic forces can obstruct the intended
movement.
Kickback zone
Never use the kickback zone of the bar
for cutting
. If the
chain is pinched or stalled in the kickback zone, the
reactive force will push the power cutter up and back
towards the user in a rotating motion causing serious or
even fatal injury.
Climbing kickback
If the kickback zone is used for cutting the reactive force
drives the bar with the chain to climb up in the cut. Do not
use the kickback zone. Use the lower quadrant of the bar
to avoid climbing kickback.
Pinching kickback
Pinching is when the cut closes and pinches the cutting
equipment. If the chain is pinched or stalled the reactive
force will be strong and you might not be able to control
the power cutter.
If the chain is pinched or stalled in the kickback zone, the
reactive force will push the power cutter up and back
towards the user in a rotating motion causing serious or
even fatal injury. Be alert for potential movement of the
work piece. Be alert to movement of the work piece or
anything else that can occur, which could cause the cut to
close and pinch the cutting equipment.
Pipe cutting
Special care should be taken when cutting in pipes. If the
pipe is not properly supported and the cut kept open
through out the cutting, the bar might be pinched in the
kickback zone and cause a severe kickback. Be
especially alert when cutting a pipe with a belled end or a
pipe in a trench that, if not properly supported, may sag
and pinch the diamond chain and guide bar.
Before starting the cut the pipe must be secure so it does
not move or roll during cutting.
If the pipe is allowed to sag and close the cut, the bar will
be pinched in the kick back zone and a severe kick back
might develop. If the pipe is properly supported the end of
the pipe will move downward, the cut will open and no
pinching will occur.
