Bosch Professional GKS 85 Manual Original página 21

OBJ_BUCH-293-003.book Page 20 Tuesday, August 21, 2007 3:45 PM
20 | English
Causes and operator prevention of kick-
back:
– Kickback is a sudden reaction to a
pinched, bound or misaligned saw blade,
causing an uncontrolled saw to lift up and
out of the workpiece toward the operator.
– When the blade is pinched or bound tightly
by the kerf closing down, the blade stalls and
the motor reaction drives the unit rapidly
back toward the operator.
– If the blade becomes twisted or mis-
aligned in the cut, the teeth at the back edge
of the blade can dig into the top surface of
the wood causing the blade to climb out of
the kerf and jump back toward the operator.
Kickback is the result of saw misuse and/or
incorrect operating procedures or conditions
and can be avoided by taking proper precau-
tions as given below.
Maintain a firm grip with both hands on the
saw and position your arms to resist kick-
back forces. Position your body to either
side of the blade, but not in line with the
blade. Kickback could cause the saw to jump
backwards, but kickback forces can be con-
trolled by the operator, if proper precautions
are taken.
When blade is binding, or when interrupting
a cut for any reason, release the trigger and
hold the saw motionless in the material un-
til the blade comes to a complete stop. Nev-
er attempt to remove the saw from the
work or pull the saw backward while the
blade is in motion or kickback may occur.
Investigate and take corrective actions to
eliminate the cause of blade binding.
When restarting a saw in the workpiece,
centre the saw blade in the kerf and check
that saw teeth are not engaged into the ma-
terial. If saw blade is binding, it may walk up
or kickback from the workpiece as the saw is
restarted.
Support large panels to minimise the risk of
blade pinching and kickback. Large panels
tend to sag under their own weight. Sup-
ports must be placed under the panel on
both sides, near the line of cut and near the
edge of the panel.
1 609 929 K67 | (21.8.07)
Do not use dull or damaged blades. Un-
sharpened or improperly set blades produce
narrow kerf causing excessive friction, blade
binding and kickback.
Blade depth and bevel adjusting locking le-
vers must be tight and secure before mak-
ing cut. If blade adjustment shifts while cut-
ting, it may cause binding and kickback.
Use extra caution when making a "plunge
cut" into existing walls or other blind areas.
The protruding blade may cut objects that
can cause kickback.
Check lower guard for proper closing be-
fore each use. Do not operate the saw if
lower guard does not move freely and close
instantly. Never clamp or tie the lower
guard into the open position. If saw is acci-
dentally dropped, lower guard may be bent.
Raise the lower guard with the retracting
handle and make sure it moves freely and
does not touch the blade or any other part, in
all angles and depths of cut.
Check the operation of the lower guard
spring. If the guard and the spring are not
operating properly, they must be serviced
before use. Lower guard may operate slug-
gishly due to damaged parts, gummy depos-
its, or a build-up of debris.
Lower guard should be retracted manually
only for special cuts such as "plunge cuts"
and "compound cuts". Raise lower guard by
retracting handle and as soon as blade en-
ters the material, the lower guard must be
released. For all other sawing, the lower
guard should operate automatically.
Always observe that the lower guard is cov-
ering the blade before placing saw down on
bench or floor. An unprotected, coasting
blade will cause the saw to walk backwards,
cutting whatever is in its path. Be aware of
the time it takes for the blade to stop after
switch is released.
Do not reach into the saw dust ejector with
your hands. They could be injured by rotat-
ing parts.
Do not work overhead with the saw. In this
manner you do not have sufficient control
over the power tool.
Bosch Power Tools