Bosch GSR Professional 120-LI Series, Original Instructions Manual

Page: 9 / 60

English | 9
Setting the rotational direction (see figure C)
The rotational direction switch (6) is used to change the ro-
tational direction of the power tool. However, this is not pos-
sible while the on/off switch
(10) is being pressed.
Right rotation: To drill and to drive in screws, press the ro-
tational direction switch (6) through to the left stop.
Left Rotation: To loosen and unscrew screws and nuts,
press the rotational direction switch (6) through to the right
stop.
Setting the Operating Mode
Drilling
GSR 120-LI:
Set the torque selector setting ring (3) to the
"drilling" symbol.
GSB 120-LI:
Set the mode selector switch (4) to the
"drilling" symbol.
Screwdriving
GSR 120-LI:
Set the torque selector setting ring (3) to the
required torque.
GSB 120-LI:
Set the mode selector switch (4) to the "screw-
driving" symbol.
Set the torque selector setting ring (3) to the
required torque.
Impact drilling
GSB 120-LI:
Set the mode selector switch (4) to the "impact
drilling" symbol.
Preselecting the Torque
The torque presetting ring (3) can be used to preselect the
required torque in 20 stages. When the correct setting is
used, the application tool will be stopped when the screw is
driven flush into the material or once the set torque has been
reached. In position
the overload clutch is deactivated,
e.g. for drilling.
When unscrewing screws, you can select a higher setting or
set the tool to the
symbol.
Mechanical gear selection
u
Only operate the gear selector (5) when the power
tool is not in use.
You can preselect two speed ranges with the gear selector
(5) .
Gear I:
Low speed range; for screwdriving or working with a large
drilling diameter.
Gear II:
High speed range; for working with a small drilling diameter.
If the gear selector switch (5) cannot be pushed all the way,
turn the tool holder (1) with the application tool slightly.
Switching on/off
To start the power tool, press and hold the on/off switch
(10) .
The lamp (11) lights up when the on/off switch (10) is lightly
or fully pressed, meaning that the work area is illuminated in
poor lighting conditions.
To
switch off the power tool, release the on/off switch (10) .
Adjusting the Speed
You can adjust the speed of the power tool when it is on by
pressing in the on/off switch
(10) to varying extents.
A light pressure on the on/off switch (10) results in a low ro-
tational speed. Increased pressure on the switch causes an
increase in speed.
Setting the speed/impact rate (GSB 120-LI)
You can adjust the speed/impact rate of the power tool when
it is on by pressing in the on/off switch
(10) to varying ex-
tents.
Applying light pressure to the on/off switch
(10) results in a
low rotational speed/impact rate. Applying increasing pres-
sure to the switch increases the speed/impact rate.
Fully automatic spindle lock (Auto-Lock)
The drill spindle, and therefore the tool holder, are locked
when the on/off switch
(10) is not pressed.
This allows screws to be driven in even when the battery is
discharged and enables the power tool to be used as a
screwdriver.
Run-out brake
Upon releasing the on/off switch (10) , the drill chuck is
slowed down, which prevents the application tool from con-
tinuing to rotate.
When driving in screws, you should therefore only release
the on/off switch
(10) once the screw has been inserted
flush into the workpiece. This way, the head of screw will not
penetrate the workpiece.
Temperature-dependent overload protection
In normal conditions of use, the power tool cannot be over-
loaded. In the event of heaving loading or the temperature
rising/falling outside the permitted battery temperature
range, the speed will be reduced. The power tool will not run
at full speed again until the permitted battery temperature
has been reached.
Practical advice
u
Only apply the power tool to the screw/nut when the
tool is switched off.
Rotating tool inserts can slip off.
After working at a low speed for an extended period, you
should operate the power tool at the maximum speed for ap-
proximately three minutes without load to cool it down.
When drilling into metal, only use sharpened HSS drills (HSS
= high-speed steel) which are in perfect condition. The
Bosch accessory range guarantees appropriate quality.
Bosch Power Tools 1 609 92A 4EE | (02.10.2018)